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linux/fs/hfs/hfs.h
Eric Sandeen cf05946250 hfs: handle more on-disk corruptions without oopsing
hfs seems prone to bad things when it encounters on disk corruption.  Many
values are read from disk, and used as lengths to memcpy, as an example.
This patch fixes up several of these problematic cases.

o sanity check the on-disk maximum key lengths on mount
  (these are set to a defined value at mkfs time and shouldn't differ)
o check on-disk node keylens against the maximum key length for each tree
o fix hfs_btree_open so that going out via free_tree: doesn't wind
  up in hfs_releasepage, which wants to follow the very pointer
  we were trying to set up:
	HFS_SB(sb)->cat_tree = hfs_btree_open()
		...
		failure gets to hfs_releasepage and tries
		to follow HFS_SB(sb)->cat_tree

Tested with the fsfuzzer; it survives more than it used to.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-08 16:10:36 -08:00

292 lines
9.1 KiB
C

/*
* linux/fs/hfs/hfs.h
*
* Copyright (C) 1995-1997 Paul H. Hargrove
* (C) 2003 Ardis Technologies <roman@ardistech.com>
* This file may be distributed under the terms of the GNU General Public License.
*/
#ifndef _HFS_H
#define _HFS_H
/* offsets to various blocks */
#define HFS_DD_BLK 0 /* Driver Descriptor block */
#define HFS_PMAP_BLK 1 /* First block of partition map */
#define HFS_MDB_BLK 2 /* Block (w/i partition) of MDB */
/* magic numbers for various disk blocks */
#define HFS_DRVR_DESC_MAGIC 0x4552 /* "ER": driver descriptor map */
#define HFS_OLD_PMAP_MAGIC 0x5453 /* "TS": old-type partition map */
#define HFS_NEW_PMAP_MAGIC 0x504D /* "PM": new-type partition map */
#define HFS_SUPER_MAGIC 0x4244 /* "BD": HFS MDB (super block) */
#define HFS_MFS_SUPER_MAGIC 0xD2D7 /* MFS MDB (super block) */
/* various FIXED size parameters */
#define HFS_SECTOR_SIZE 512 /* size of an HFS sector */
#define HFS_SECTOR_SIZE_BITS 9 /* log_2(HFS_SECTOR_SIZE) */
#define HFS_NAMELEN 31 /* maximum length of an HFS filename */
#define HFS_MAX_NAMELEN 128
#define HFS_MAX_VALENCE 32767U
#define HFS_BAD_KEYLEN 0xFF
/* Meanings of the drAtrb field of the MDB,
* Reference: _Inside Macintosh: Files_ p. 2-61
*/
#define HFS_SB_ATTRIB_HLOCK (1 << 7)
#define HFS_SB_ATTRIB_UNMNT (1 << 8)
#define HFS_SB_ATTRIB_SPARED (1 << 9)
#define HFS_SB_ATTRIB_INCNSTNT (1 << 11)
#define HFS_SB_ATTRIB_SLOCK (1 << 15)
/* Some special File ID numbers */
#define HFS_POR_CNID 1 /* Parent Of the Root */
#define HFS_ROOT_CNID 2 /* ROOT directory */
#define HFS_EXT_CNID 3 /* EXTents B-tree */
#define HFS_CAT_CNID 4 /* CATalog B-tree */
#define HFS_BAD_CNID 5 /* BAD blocks file */
#define HFS_ALLOC_CNID 6 /* ALLOCation file (HFS+) */
#define HFS_START_CNID 7 /* STARTup file (HFS+) */
#define HFS_ATTR_CNID 8 /* ATTRibutes file (HFS+) */
#define HFS_EXCH_CNID 15 /* ExchangeFiles temp id */
#define HFS_FIRSTUSER_CNID 16
/* values for hfs_cat_rec.cdrType */
#define HFS_CDR_DIR 0x01 /* folder (directory) */
#define HFS_CDR_FIL 0x02 /* file */
#define HFS_CDR_THD 0x03 /* folder (directory) thread */
#define HFS_CDR_FTH 0x04 /* file thread */
/* legal values for hfs_ext_key.FkType and hfs_file.fork */
#define HFS_FK_DATA 0x00
#define HFS_FK_RSRC 0xFF
/* bits in hfs_fil_entry.Flags */
#define HFS_FIL_LOCK 0x01 /* locked */
#define HFS_FIL_THD 0x02 /* file thread */
#define HFS_FIL_DOPEN 0x04 /* data fork open */
#define HFS_FIL_ROPEN 0x08 /* resource fork open */
#define HFS_FIL_DIR 0x10 /* directory (always clear) */
#define HFS_FIL_NOCOPY 0x40 /* copy-protected file */
#define HFS_FIL_USED 0x80 /* open */
/* bits in hfs_dir_entry.Flags. dirflags is 16 bits. */
#define HFS_DIR_LOCK 0x01 /* locked */
#define HFS_DIR_THD 0x02 /* directory thread */
#define HFS_DIR_INEXPFOLDER 0x04 /* in a shared area */
#define HFS_DIR_MOUNTED 0x08 /* mounted */
#define HFS_DIR_DIR 0x10 /* directory (always set) */
#define HFS_DIR_EXPFOLDER 0x20 /* share point */
/* bits hfs_finfo.fdFlags */
#define HFS_FLG_INITED 0x0100
#define HFS_FLG_LOCKED 0x1000
#define HFS_FLG_INVISIBLE 0x4000
/*======== HFS structures as they appear on the disk ========*/
/* Pascal-style string of up to 31 characters */
struct hfs_name {
u8 len;
u8 name[HFS_NAMELEN];
} __packed;
struct hfs_point {
__be16 v;
__be16 h;
} __packed;
struct hfs_rect {
__be16 top;
__be16 left;
__be16 bottom;
__be16 right;
} __packed;
struct hfs_finfo {
__be32 fdType;
__be32 fdCreator;
__be16 fdFlags;
struct hfs_point fdLocation;
__be16 fdFldr;
} __packed;
struct hfs_fxinfo {
__be16 fdIconID;
u8 fdUnused[8];
__be16 fdComment;
__be32 fdPutAway;
} __packed;
struct hfs_dinfo {
struct hfs_rect frRect;
__be16 frFlags;
struct hfs_point frLocation;
__be16 frView;
} __packed;
struct hfs_dxinfo {
struct hfs_point frScroll;
__be32 frOpenChain;
__be16 frUnused;
__be16 frComment;
__be32 frPutAway;
} __packed;
union hfs_finder_info {
struct {
struct hfs_finfo finfo;
struct hfs_fxinfo fxinfo;
} file;
struct {
struct hfs_dinfo dinfo;
struct hfs_dxinfo dxinfo;
} dir;
} __packed;
/* Cast to a pointer to a generic bkey */
#define HFS_BKEY(X) (((void)((X)->KeyLen)), ((struct hfs_bkey *)(X)))
/* The key used in the catalog b-tree: */
struct hfs_cat_key {
u8 key_len; /* number of bytes in the key */
u8 reserved; /* padding */
__be32 ParID; /* CNID of the parent dir */
struct hfs_name CName; /* The filename of the entry */
} __packed;
/* The key used in the extents b-tree: */
struct hfs_ext_key {
u8 key_len; /* number of bytes in the key */
u8 FkType; /* HFS_FK_{DATA,RSRC} */
__be32 FNum; /* The File ID of the file */
__be16 FABN; /* allocation blocks number*/
} __packed;
typedef union hfs_btree_key {
u8 key_len; /* number of bytes in the key */
struct hfs_cat_key cat;
struct hfs_ext_key ext;
} hfs_btree_key;
#define HFS_MAX_CAT_KEYLEN (sizeof(struct hfs_cat_key) - sizeof(u8))
#define HFS_MAX_EXT_KEYLEN (sizeof(struct hfs_ext_key) - sizeof(u8))
typedef union hfs_btree_key btree_key;
struct hfs_extent {
__be16 block;
__be16 count;
};
typedef struct hfs_extent hfs_extent_rec[3];
/* The catalog record for a file */
struct hfs_cat_file {
s8 type; /* The type of entry */
u8 reserved;
u8 Flags; /* Flags such as read-only */
s8 Typ; /* file version number = 0 */
struct hfs_finfo UsrWds; /* data used by the Finder */
__be32 FlNum; /* The CNID */
__be16 StBlk; /* obsolete */
__be32 LgLen; /* The logical EOF of the data fork*/
__be32 PyLen; /* The physical EOF of the data fork */
__be16 RStBlk; /* obsolete */
__be32 RLgLen; /* The logical EOF of the rsrc fork */
__be32 RPyLen; /* The physical EOF of the rsrc fork */
__be32 CrDat; /* The creation date */
__be32 MdDat; /* The modified date */
__be32 BkDat; /* The last backup date */
struct hfs_fxinfo FndrInfo; /* more data for the Finder */
__be16 ClpSize; /* number of bytes to allocate
when extending files */
hfs_extent_rec ExtRec; /* first extent record
for the data fork */
hfs_extent_rec RExtRec; /* first extent record
for the resource fork */
u32 Resrv; /* reserved by Apple */
} __packed;
/* the catalog record for a directory */
struct hfs_cat_dir {
s8 type; /* The type of entry */
u8 reserved;
__be16 Flags; /* flags */
__be16 Val; /* Valence: number of files and
dirs in the directory */
__be32 DirID; /* The CNID */
__be32 CrDat; /* The creation date */
__be32 MdDat; /* The modification date */
__be32 BkDat; /* The last backup date */
struct hfs_dinfo UsrInfo; /* data used by the Finder */
struct hfs_dxinfo FndrInfo; /* more data used by Finder */
u8 Resrv[16]; /* reserved by Apple */
} __packed;
/* the catalog record for a thread */
struct hfs_cat_thread {
s8 type; /* The type of entry */
u8 reserved[9]; /* reserved by Apple */
__be32 ParID; /* CNID of parent directory */
struct hfs_name CName; /* The name of this entry */
} __packed;
/* A catalog tree record */
typedef union hfs_cat_rec {
s8 type; /* The type of entry */
struct hfs_cat_file file;
struct hfs_cat_dir dir;
struct hfs_cat_thread thread;
} hfs_cat_rec;
struct hfs_mdb {
__be16 drSigWord; /* Signature word indicating fs type */
__be32 drCrDate; /* fs creation date/time */
__be32 drLsMod; /* fs modification date/time */
__be16 drAtrb; /* fs attributes */
__be16 drNmFls; /* number of files in root directory */
__be16 drVBMSt; /* location (in 512-byte blocks)
of the volume bitmap */
__be16 drAllocPtr; /* location (in allocation blocks)
to begin next allocation search */
__be16 drNmAlBlks; /* number of allocation blocks */
__be32 drAlBlkSiz; /* bytes in an allocation block */
__be32 drClpSiz; /* clumpsize, the number of bytes to
allocate when extending a file */
__be16 drAlBlSt; /* location (in 512-byte blocks)
of the first allocation block */
__be32 drNxtCNID; /* CNID to assign to the next
file or directory created */
__be16 drFreeBks; /* number of free allocation blocks */
u8 drVN[28]; /* the volume label */
__be32 drVolBkUp; /* fs backup date/time */
__be16 drVSeqNum; /* backup sequence number */
__be32 drWrCnt; /* fs write count */
__be32 drXTClpSiz; /* clumpsize for the extents B-tree */
__be32 drCTClpSiz; /* clumpsize for the catalog B-tree */
__be16 drNmRtDirs; /* number of directories in
the root directory */
__be32 drFilCnt; /* number of files in the fs */
__be32 drDirCnt; /* number of directories in the fs */
u8 drFndrInfo[32]; /* data used by the Finder */
__be16 drEmbedSigWord; /* embedded volume signature */
__be32 drEmbedExtent; /* starting block number (xdrStABN)
and number of allocation blocks
(xdrNumABlks) occupied by embedded
volume */
__be32 drXTFlSize; /* bytes in the extents B-tree */
hfs_extent_rec drXTExtRec; /* extents B-tree's first 3 extents */
__be32 drCTFlSize; /* bytes in the catalog B-tree */
hfs_extent_rec drCTExtRec; /* catalog B-tree's first 3 extents */
} __packed;
/*======== Data structures kept in memory ========*/
struct hfs_readdir_data {
struct list_head list;
struct file *file;
struct hfs_cat_key key;
};
#endif