Source to bsd/hfs/hfs_format.h
/*
* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* The contents of this file constitute Original Code as defined in and
* are subject to the Apple Public Source License Version 1.1 (the
* "License"). You may not use this file except in compliance with the
* License. Please obtain a copy of the License at
* http://www.apple.com/publicsource and read it before using this file.
*
* This Original Code and all software distributed under the License are
* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
* License for the specific language governing rights and limitations
* under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
#ifndef __HFS_FORMAT__
#define __HFS_FORMAT__
/*
* hfs_format.c
*
* This file describes the on-disk format for hfs/HFS Plus volumes.
* The HFS Plus volume format is desciibed in detail in Apple Technote 1150.
*
* http://developer.apple.com/technotes/tn/tn1150.html
*
*/
#ifdef __cplusplus
extern "C" {
#endif
/* some on disk hfs structures have 68K alignment (misaligned) */
#pragma options align=mac68k
/* Signatures used to differentiate between HFS and HFS Plus volumes */
enum {
kHFSSigWord = 0x4244, /* 'BD' in ASCII */
kHFSPlusSigWord = 0x482B, /* 'H+' in ASCII */
kHFSPlusVersion = 0x0004, /* will change as format changes */
/* version 4 shipped with Mac OS 8.1 */
kHFSPlusMountVersion = 0x31302E30 /* '10.0' for Mac OS X */
};
/*
* Mac OS X special directory for linked and/or deleted files (HFS Plus only)
*
* to make this folder name sort last...
* it has 0xFFE5 Unicode prefix (0xEF, 0xBF, 0xA5 in UTF-8)
*/
#define HFSPLUSMETADATAFOLDER "\xEF\xBF\xA5\xEF\xBF\xA5\xEF\xBF\xA5 HFS Private Meta Data"
/*
* Files in the HFS Private Meta Data folder have one of the following
* prefixes followed by the file ID in decimal (no leading zeros).
* e.g. FileNodeData3296
*/
#define HFS_LINK_PREFIX "FileNodeData"
#define HFS_DELETE_PREFIX "DeletedFile"
/* Unicode strings are used for HFS Plus file and folder names */
struct HFSUniStr255 {
u_int16_t length; /* number of unicode characters */
u_int16_t unicode[255]; /* unicode characters */
};
typedef struct HFSUniStr255 HFSUniStr255;
typedef const HFSUniStr255 *ConstHFSUniStr255Param;
enum {
kHFSMaxVolumeNameChars = 27,
kHFSMaxFileNameChars = 31,
kHFSPlusMaxFileNameChars = 255
};
/* Extent overflow file data structures */
/* HFS Extent key */
struct HFSExtentKey {
u_int8_t keyLength; /* length of key, excluding this field */
u_int8_t forkType; /* 0 = data fork, FF = resource fork */
u_int32_t fileID; /* file ID */
u_int16_t startBlock; /* first file allocation block number in this extent */
};
typedef struct HFSExtentKey HFSExtentKey;
/* HFS Plus Extent key */
struct HFSPlusExtentKey {
u_int16_t keyLength; /* length of key, excluding this field */
u_int8_t forkType; /* 0 = data fork, FF = resource fork */
u_int8_t pad; /* make the other fields align on 32-bit boundary */
u_int32_t fileID; /* file ID */
u_int32_t startBlock; /* first file allocation block number in this extent */
};
typedef struct HFSPlusExtentKey HFSPlusExtentKey;
/* Number of extent descriptors per extent record */
enum {
kHFSExtentDensity = 3,
kHFSPlusExtentDensity = 8
};
/* HFS extent descriptor */
struct HFSExtentDescriptor {
u_int16_t startBlock; /* first allocation block */
u_int16_t blockCount; /* number of allocation blocks */
};
typedef struct HFSExtentDescriptor HFSExtentDescriptor;
/* HFS Plus extent descriptor */
struct HFSPlusExtentDescriptor {
u_int32_t startBlock; /* first allocation block */
u_int32_t blockCount; /* number of allocation blocks */
};
typedef struct HFSPlusExtentDescriptor HFSPlusExtentDescriptor;
/* HFS extent record */
typedef HFSExtentDescriptor HFSExtentRecord[3];
/* HFS Plus extent record */
typedef HFSPlusExtentDescriptor HFSPlusExtentRecord[8];
/* Finder information */
struct FndrFileInfo {
u_int32_t fdType; /* file type */
u_int32_t fdCreator; /* file creator */
u_int16_t fdFlags; /* Finder flags */
struct {
int16_t v; /* file's location */
int16_t h;
} fdLocation;
int16_t opaque;
};
typedef struct FndrFileInfo FndrFileInfo;
struct FndrDirInfo {
struct { /* folder's window rectangle */
int16_t top;
int16_t left;
int16_t bottom;
int16_t right;
} frRect;
unsigned short frFlags; /* Finder flags */
struct {
u_int16_t v; /* folder's location */
u_int16_t h;
} frLocation;
int16_t opaque;
};
typedef struct FndrDirInfo FndrDirInfo;
struct FndrOpaqueInfo {
int8_t opaque[16];
};
typedef struct FndrOpaqueInfo FndrOpaqueInfo;
/* HFS Plus Fork data info - 80 bytes */
struct HFSPlusForkData {
u_int64_t logicalSize; /* fork's logical size in bytes */
u_int32_t clumpSize; /* fork's clump size in bytes */
u_int32_t totalBlocks; /* total blocks used by this fork */
HFSPlusExtentRecord extents; /* initial set of extents */
};
typedef struct HFSPlusForkData HFSPlusForkData;
/* HFS Plus Permissions info - 16 bytes */
struct HFSPlusPermissions {
u_int32_t ownerID; /* user or group ID of file/folder owner */
u_int32_t groupID; /* additional user of group ID */
u_int32_t permissions; /* permissions (bytes: unused, owner, group, everyone) */
u_int32_t specialDevice; /* UNIX: device for character or block special file */
};
typedef struct HFSPlusPermissions HFSPlusPermissions;
/* Catalog file data structures */
enum {
kHFSRootParentID = 1, /* Parent ID of the root folder */
kHFSRootFolderID = 2, /* Folder ID of the root folder */
kHFSExtentsFileID = 3, /* File ID of the extents file */
kHFSCatalogFileID = 4, /* File ID of the catalog file */
kHFSBadBlockFileID = 5, /* File ID of the bad allocation block file */
kHFSAllocationFileID = 6, /* File ID of the allocation file (HFS Plus only) */
kHFSStartupFileID = 7, /* File ID of the startup file (HFS Plus only) */
kHFSAttributesFileID = 8, /* File ID of the attribute file (HFS Plus only) */
kHFSBogusExtentFileID = 15, /* Used for exchanging extents in extents file */
kHFSFirstUserCatalogNodeID = 16
};
/* HFS catalog key */
struct HFSCatalogKey {
u_int8_t keyLength; /* key length (in bytes) */
u_int8_t reserved; /* reserved (set to zero) */
u_int32_t parentID; /* parent folder ID */
u_char nodeName[kHFSMaxFileNameChars + 1]; /* catalog node name */
};
typedef struct HFSCatalogKey HFSCatalogKey;
/* HFS Plus catalog key */
struct HFSPlusCatalogKey {
u_int16_t keyLength; /* key length (in bytes) */
u_int32_t parentID; /* parent folder ID */
HFSUniStr255 nodeName; /* catalog node name */
};
typedef struct HFSPlusCatalogKey HFSPlusCatalogKey;
/* Catalog record types */
enum {
/* HFS Catalog Records */
kHFSFolderRecord = 0x0100, /* Folder record */
kHFSFileRecord = 0x0200, /* File record */
kHFSFolderThreadRecord = 0x0300, /* Folder thread record */
kHFSFileThreadRecord = 0x0400, /* File thread record */
/* HFS Plus Catalog Records */
kHFSPlusFolderRecord = 1, /* Folder record */
kHFSPlusFileRecord = 2, /* File record */
kHFSPlusFolderThreadRecord = 3, /* Folder thread record */
kHFSPlusFileThreadRecord = 4 /* File thread record */
};
/* Catalog file record flags */
enum {
kHFSFileLockedBit = 0x0000, /* file is locked and cannot be written to */
kHFSFileLockedMask = 0x0001,
kHFSThreadExistsBit = 0x0001, /* a file thread record exists for this file */
kHFSThreadExistsMask = 0x0002
};
/* HFS catalog folder record - 70 bytes */
struct HFSCatalogFolder {
int16_t recordType; /* == kHFSFolderRecord */
u_int16_t flags; /* folder flags */
u_int16_t valence; /* folder valence */
u_int32_t folderID; /* folder ID */
u_int32_t createDate; /* date and time of creation */
u_int32_t modifyDate; /* date and time of last modification */
u_int32_t backupDate; /* date and time of last backup */
FndrDirInfo userInfo; /* Finder information */
FndrOpaqueInfo finderInfo; /* additional Finder information */
u_int32_t reserved[4]; /* reserved - initialized as zero */
};
typedef struct HFSCatalogFolder HFSCatalogFolder;
/* HFS Plus catalog folder record - 88 bytes */
struct HFSPlusCatalogFolder {
int16_t recordType; /* == kHFSPlusFolderRecord */
u_int16_t flags; /* file flags */
u_int32_t valence; /* folder's valence (limited to 2^16 in Mac OS) */
u_int32_t folderID; /* folder ID */
u_int32_t createDate; /* date and time of creation */
u_int32_t contentModDate; /* date and time of last content modification */
u_int32_t attributeModDate; /* date and time of last attribute modification */
u_int32_t accessDate; /* date and time of last access (MacOS X only) */
u_int32_t backupDate; /* date and time of last backup */
HFSPlusPermissions permissions; /* permissions (for MacOS X) */
FndrDirInfo userInfo; /* Finder information */
FndrOpaqueInfo finderInfo; /* additional Finder information */
u_int32_t textEncoding; /* hint for name conversions */
u_int32_t reserved; /* reserved - initialized as zero */
};
typedef struct HFSPlusCatalogFolder HFSPlusCatalogFolder;
/* HFS catalog file record - 102 bytes */
struct HFSCatalogFile {
int16_t recordType; /* == kHFSFileRecord */
u_int8_t flags; /* file flags */
int8_t fileType; /* file type (unused ?) */
FndrFileInfo userInfo; /* Finder information */
u_int32_t fileID; /* file ID */
u_int16_t dataStartBlock; /* not used - set to zero */
int32_t dataLogicalSize; /* logical EOF of data fork */
int32_t dataPhysicalSize; /* physical EOF of data fork */
u_int16_t rsrcStartBlock; /* not used - set to zero */
int32_t rsrcLogicalSize; /* logical EOF of resource fork */
int32_t rsrcPhysicalSize; /* physical EOF of resource fork */
u_int32_t createDate; /* date and time of creation */
u_int32_t modifyDate; /* date and time of last modification */
u_int32_t backupDate; /* date and time of last backup */
FndrOpaqueInfo finderInfo; /* additional Finder information */
u_int16_t clumpSize; /* file clump size (not used) */
HFSExtentRecord dataExtents; /* first data fork extent record */
HFSExtentRecord rsrcExtents; /* first resource fork extent record */
u_int32_t reserved; /* reserved - initialized as zero */
};
typedef struct HFSCatalogFile HFSCatalogFile;
/* HFS Plus catalog file record - 248 bytes */
struct HFSPlusCatalogFile {
int16_t recordType; /* == kHFSPlusFileRecord */
u_int16_t flags; /* file flags */
u_int32_t linkCount; /* used by Mac OS X */
u_int32_t fileID; /* file ID */
u_int32_t createDate; /* date and time of creation */
u_int32_t contentModDate; /* date and time of last content modification */
u_int32_t attributeModDate; /* date and time of last attribute modification */
u_int32_t accessDate; /* date and time of last access (MacOS X only) */
u_int32_t backupDate; /* date and time of last backup */
HFSPlusPermissions permissions; /* permissions (for MacOS X) */
FndrFileInfo userInfo; /* Finder information */
FndrOpaqueInfo finderInfo; /* additional Finder information */
u_int32_t textEncoding; /* hint for name conversions */
u_int32_t reserved2; /* reserved - initialized as zero */
/* Note: these start on double long (64 bit) boundry */
HFSPlusForkData dataFork; /* size and block data for data fork */
HFSPlusForkData resourceFork; /* size and block data for resource fork */
};
typedef struct HFSPlusCatalogFile HFSPlusCatalogFile;
/* HFS catalog thread record - 46 bytes */
struct HFSCatalogThread {
int16_t recordType; /* == kHFSFolderThreadRecord or kHFSFileThreadRecord */
int32_t reserved[2]; /* reserved - initialized as zero */
u_int32_t parentID; /* parent ID for this catalog node */
u_char nodeName[kHFSMaxFileNameChars + 1]; /* name of this catalog node */
};
typedef struct HFSCatalogThread HFSCatalogThread;
/* HFS Plus catalog thread record -- 264 bytes */
struct HFSPlusCatalogThread {
int16_t recordType; /* == kHFSPlusFolderThreadRecord or kHFSPlusFileThreadRecord */
int16_t reserved; /* reserved - initialized as zero */
u_int32_t parentID; /* parent ID for this catalog node */
HFSUniStr255 nodeName; /* name of this catalog node (variable length) */
};
typedef struct HFSPlusCatalogThread HFSPlusCatalogThread;
/*
These are the types of records in the attribute B-tree. The values were
chosen so that they wouldn't conflict with the catalog record types.
*/
enum {
kHFSPlusAttrInlineData = 0x10, /* if size < kAttrOverflowSize */
kHFSPlusAttrForkData = 0x20, /* if size >= kAttrOverflowSize */
kHFSPlusAttrExtents = 0x30 /* overflow extents for large attributes */
};
/*
HFSPlusAttrInlineData
For small attributes, whose entire value is stored within this one
B-tree record.
There would not be any other records for this attribute.
*/
struct HFSPlusAttrInlineData {
u_int32_t recordType; /* == kHFSPlusAttrInlineData*/
u_int32_t reserved;
u_int32_t logicalSize; /* size in bytes of userData*/
u_int8_t userData[2]; /* variable length; space allocated is a multiple of 2 bytes*/
};
typedef struct HFSPlusAttrInlineData HFSPlusAttrInlineData;
/*
HFSPlusAttrForkData
For larger attributes, whose value is stored in allocation blocks.
If the attribute has more than 8 extents, there will be additonal
records (of type HFSPlusAttrExtents) for this attribute.
*/
struct HFSPlusAttrForkData {
u_int32_t recordType; /* == kHFSPlusAttrForkData*/
u_int32_t reserved;
HFSPlusForkData theFork; /* size and first extents of value*/
};
typedef struct HFSPlusAttrForkData HFSPlusAttrForkData;
/*
HFSPlusAttrExtents
This record contains information about overflow extents for large,
fragmented attributes.
*/
struct HFSPlusAttrExtents {
u_int32_t recordType; /* == kHFSPlusAttrExtents*/
u_int32_t reserved;
HFSPlusExtentRecord extents; /* additional extents*/
};
typedef struct HFSPlusAttrExtents HFSPlusAttrExtents;
/* A generic Attribute Record*/
union HFSPlusAttrRecord {
u_int32_t recordType;
HFSPlusAttrInlineData inlineData;
HFSPlusAttrForkData forkData;
HFSPlusAttrExtents overflowExtents;
};
typedef union HFSPlusAttrRecord HFSPlusAttrRecord;
/* Key and node lengths */
enum {
kHFSPlusExtentKeyMaximumLength = sizeof(HFSPlusExtentKey) - sizeof(u_int16_t),
kHFSExtentKeyMaximumLength = sizeof(HFSExtentKey) - sizeof(u_int8_t),
kHFSPlusCatalogKeyMaximumLength = sizeof(HFSPlusCatalogKey) - sizeof(u_int16_t),
kHFSPlusCatalogKeyMinimumLength = kHFSPlusCatalogKeyMaximumLength - sizeof(HFSUniStr255) + sizeof(u_int16_t),
kHFSCatalogKeyMaximumLength = sizeof(HFSCatalogKey) - sizeof(u_int8_t),
kHFSCatalogKeyMinimumLength = kHFSCatalogKeyMaximumLength - (kHFSMaxFileNameChars + 1 + sizeof(u_int8_t)),
kHFSPlusCatalogMinNodeSize = 4096,
kHFSPlusExtentMinNodeSize = 512,
kHFSPlusAttrMinNodeSize = 4096
};
/* HFS and HFS Plus volume attribute bits */
enum {
/* Bits 0-6 are reserved (always cleared by MountVol call) */
kHFSVolumeHardwareLockBit = 7, /* volume is locked by hardware */
kHFSVolumeUnmountedBit = 8, /* volume was successfully unmounted */
kHFSVolumeSparedBlocksBit = 9, /* volume has bad blocks spared */
kHFSVolumeNoCacheRequiredBit = 10, /* don't cache volume blocks (i.e. RAM or ROM disk) */
kHFSBootVolumeInconsistentBit = 11, /* boot volume is inconsistent (System 7.6 and later) */
/* Bits 12-14 are reserved for future use */
kHFSVolumeSoftwareLockBit = 15, /* volume is locked by software */
kHFSVolumeHardwareLockMask = 1 << kHFSVolumeHardwareLockBit,
kHFSVolumeUnmountedMask = 1 << kHFSVolumeUnmountedBit,
kHFSVolumeSparedBlocksMask = 1 << kHFSVolumeSparedBlocksBit,
kHFSVolumeNoCacheRequiredMask = 1 << kHFSVolumeNoCacheRequiredBit,
kHFSBootVolumeInconsistentMask = 1 << kHFSBootVolumeInconsistentBit,
kHFSVolumeSoftwareLockMask = 1 << kHFSVolumeSoftwareLockBit,
kHFSMDBAttributesMask = 0x8380
};
/* HFS Master Directory Block - 162 bytes */
/* Stored at sector #2 (3rd sector) and second-to-last sector. */
struct HFSMasterDirectoryBlock {
u_int16_t drSigWord; /* == kHFSSigWord */
u_int32_t drCrDate; /* date and time of volume creation */
u_int32_t drLsMod; /* date and time of last modification */
u_int16_t drAtrb; /* volume attributes */
u_int16_t drNmFls; /* number of files in root folder */
u_int16_t drVBMSt; /* first block of volume bitmap */
u_int16_t drAllocPtr; /* start of next allocation search */
u_int16_t drNmAlBlks; /* number of allocation blocks in volume */
u_int32_t drAlBlkSiz; /* size (in bytes) of allocation blocks */
u_int32_t drClpSiz; /* default clump size */
u_int16_t drAlBlSt; /* first allocation block in volume */
u_int32_t drNxtCNID; /* next unused catalog node ID */
u_int16_t drFreeBks; /* number of unused allocation blocks */
u_char drVN[kHFSMaxVolumeNameChars + 1]; /* volume name */
u_int32_t drVolBkUp; /* date and time of last backup */
u_int16_t drVSeqNum; /* volume backup sequence number */
u_int32_t drWrCnt; /* volume write count */
u_int32_t drXTClpSiz; /* clump size for extents overflow file */
u_int32_t drCTClpSiz; /* clump size for catalog file */
u_int16_t drNmRtDirs; /* number of directories in root folder */
u_int32_t drFilCnt; /* number of files in volume */
u_int32_t drDirCnt; /* number of directories in volume */
u_int32_t drFndrInfo[8]; /* information used by the Finder */
u_int16_t drEmbedSigWord; /* embedded volume signature (formerly drVCSize) */
HFSExtentDescriptor drEmbedExtent; /* embedded volume location and size (formerly drVBMCSize and drCtlCSize) */
u_int32_t drXTFlSize; /* size of extents overflow file */
HFSExtentRecord drXTExtRec; /* extent record for extents overflow file */
u_int32_t drCTFlSize; /* size of catalog file */
HFSExtentRecord drCTExtRec; /* extent record for catalog file */
};
typedef struct HFSMasterDirectoryBlock HFSMasterDirectoryBlock;
/* HFS Plus Volume Header - 512 bytes */
/* Stored at sector #2 (3rd sector) and second-to-last sector. */
struct HFSPlusVolumeHeader {
u_int16_t signature; /* == kHFSPlusSigWord */
u_int16_t version; /* == kHFSPlusVersion */
u_int32_t attributes; /* volume attributes */
u_int32_t lastMountedVersion; /* implementation version which last mounted volume */
u_int32_t reserved; /* reserved - initialized as zero */
u_int32_t createDate; /* date and time of volume creation */
u_int32_t modifyDate; /* date and time of last modification */
u_int32_t backupDate; /* date and time of last backup */
u_int32_t checkedDate; /* date and time of last disk check */
u_int32_t fileCount; /* number of files in volume */
u_int32_t folderCount; /* number of directories in volume */
u_int32_t blockSize; /* size (in bytes) of allocation blocks */
u_int32_t totalBlocks; /* number of allocation blocks in volume (includes this header and VBM*/
u_int32_t freeBlocks; /* number of unused allocation blocks */
u_int32_t nextAllocation; /* start of next allocation search */
u_int32_t rsrcClumpSize; /* default resource fork clump size */
u_int32_t dataClumpSize; /* default data fork clump size */
u_int32_t nextCatalogID; /* next unused catalog node ID */
u_int32_t writeCount; /* volume write count */
u_int64_t encodingsBitmap; /* which encodings have been use on this volume */
u_int8_t finderInfo[32]; /* information used by the Finder */
HFSPlusForkData allocationFile; /* allocation bitmap file */
HFSPlusForkData extentsFile; /* extents B-tree file */
HFSPlusForkData catalogFile; /* catalog B-tree file */
HFSPlusForkData attributesFile; /* extended attributes B-tree file */
HFSPlusForkData startupFile; /* boot file (secondary loader) */
};
typedef struct HFSPlusVolumeHeader HFSPlusVolumeHeader;
/* B-tree structures */
enum BTreeKeyLimits{
kMaxKeyLength = 520
};
union BTreeKey{
u_int8_t length8;
u_int16_t length16;
u_int8_t rawData [kMaxKeyLength+2];
};
typedef union BTreeKey BTreeKey;
/* BTNodeDescriptor -- Every B-tree node starts with these fields. */
struct BTNodeDescriptor {
u_int32_t fLink; /* next node at this level*/
u_int32_t bLink; /* previous node at this level*/
int8_t kind; /* kind of node (leaf, index, header, map)*/
u_int8_t height; /* zero for header, map; child is one more than parent*/
u_int16_t numRecords; /* number of records in this node*/
u_int16_t reserved; /* reserved - initialized as zero */
};
typedef struct BTNodeDescriptor BTNodeDescriptor;
/* Constants for BTNodeDescriptor kind */
enum {
kBTLeafNode = -1,
kBTIndexNode = 0,
kBTHeaderNode = 1,
kBTMapNode = 2
};
/* BTHeaderRec -- The first record of a B-tree header node */
struct BTHeaderRec {
u_int16_t treeDepth; /* maximum height (usually leaf nodes) */
u_int32_t rootNode; /* node number of root node */
u_int32_t leafRecords; /* number of leaf records in all leaf nodes */
u_int32_t firstLeafNode; /* node number of first leaf node */
u_int32_t lastLeafNode; /* node number of last leaf node */
u_int16_t nodeSize; /* size of a node, in bytes */
u_int16_t maxKeyLength; /* reserved */
u_int32_t totalNodes; /* total number of nodes in tree */
u_int32_t freeNodes; /* number of unused (free) nodes in tree */
u_int16_t reserved1; /* unused */
u_int32_t clumpSize; /* reserved */
u_int8_t btreeType; /* reserved */
u_int8_t reserved2; /* reserved */
u_int32_t attributes; /* persistent attributes about the tree */
u_int32_t reserved3[16]; /* reserved */
};
typedef struct BTHeaderRec BTHeaderRec;
/* Constants for BTHeaderRec attributes */
enum {
kBTBadCloseMask = 0x00000001, /* reserved */
kBTBigKeysMask = 0x00000002, /* key length field is 16 bits */
kBTVariableIndexKeysMask = 0x00000004 /* keys in index nodes are variable length */
};
#pragma options align=reset
#ifdef __cplusplus
}
#endif
#endif /* __HFS_FORMAT__ */