* Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.

/* $NetBSD: denode.h,v 1.29 2021/10/23 16:58:17 thorpej Exp $ */

/*-
* Copyright (C) 1994, 1995, 1997 Wolfgang Solfrank.
* Copyright (C) 1994, 1995, 1997 TooLs GmbH.
* All rights reserved.
* Original code by Paul Popelka ([email protected]) (see below).
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Written by Paul Popelka ([email protected])
*
* You can do anything you want with this software, just don't say you wrote
* it, and don't remove this notice.
*
* This software is provided "as is".
*
* The author supplies this software to be publicly redistributed on the
* understanding that the author is not responsible for the correct
* functioning of this software in any circumstances and is not liable for
* any damages caused by this software.
*
* October 1992
*/
#ifndef _MSDOSFS_DENODE_H_
#define _MSDOSFS_DENODE_H_

#ifndef MAKEFS
#include <miscfs/genfs/genfs_node.h>
#else
struct genfs_node {
};
struct vnode;
struct msdosfsmount;
struct buf;
#endif

/*
* This is the pc filesystem specific portion of the vnode structure.
*
* To describe a file uniquely the de_dirclust, de_diroffset, and
* de_StartCluster fields are used.
*
* de_dirclust contains the cluster number of the directory cluster
* containing the entry for a file or directory.
* de_diroffset is the index into the cluster for the entry describing
* a file or directory.
* de_StartCluster is the number of the first cluster of the file or directory.
*
* Now to describe the quirks of the pc filesystem.
* - Clusters 0 and 1 are reserved.
* - The first allocatable cluster is 2.
* - The root directory is of fixed size and all blocks that make it up
* are contiguous.
* - Cluster 0 refers to the root directory when it is found in the
* startcluster field of a directory entry that points to another directory.
* - Cluster 0 implies a 0 length file when found in the start cluster field
* of a directory entry that points to a file.
* - You can't use the cluster number 0 to derive the address of the root
* directory.
* - Multiple directory entries can point to a directory. The entry in the
* parent directory points to a child directory. Any directories in the
* child directory contain a ".." entry that points back to the parent.
* The child directory itself contains a "." entry that points to itself.
* - The root directory does not contain a "." or ".." entry.
* - Directory entries for directories are never changed once they are created
* (except when removed). The size stays 0, and the last modification time
* is never changed. This is because so many directory entries can point to
* the physical clusters that make up a directory. It would lead to an
* update nightmare.
* - The length field in a directory entry pointing to a directory contains 0
* (always). The only way to find the end of a directory is to follow the
* cluster chain until the "last cluster" marker is found.
*
* My extensions to make this house of cards work. These apply only to the in
* memory copy of the directory entry.
* - A reference count for each denode will be kept since dos doesn't keep such
* things.
*/

/*
* Internal pseudo-offset for (nonexistent) directory entry for the root
* dir in the root dir
*/
#define MSDOSFSROOT_OFS 0x1fffffff

/*
* The FAT cache structure. fc_fsrcn is the filesystem relative cluster
* number that corresponds to the file relative cluster number in this
* structure (fc_frcn).
*/
struct fatcache {
u_long fc_frcn; /* file relative cluster number */
u_long fc_fsrcn; /* filesystem relative cluster number */
};

/*
* The FAT entry cache as it stands helps make extending files a "quick"
* operation by avoiding having to scan the FAT to discover the last
* cluster of the file. The cache also helps sequential reads by
* remembering the last cluster read from the file. This also prevents us
* from having to rescan the FAT to find the next cluster to read. This
* cache is probably pretty worthless if a file is opened by multiple
* processes.
*/
#define FC_SIZE 3 /* number of entries in the cache */
#define FC_LASTMAP 0 /* entry the last call to pcbmap() resolved
* to */
#define FC_LASTFC 1 /* entry for the last cluster in the file */
#define FC_NEXTTOLASTFC 2 /* entry for a close to the last cluster in the file */

#define FCE_EMPTY 0xffffffff /* doesn't represent an actual cluster # */

/*
* Set a slot in the FAT cache.
*/
#define fc_setcache(dep, slot, frcn, fsrcn) \
(dep)->de_fc[slot].fc_frcn = frcn; \
(dep)->de_fc[slot].fc_fsrcn = fsrcn;

#define fc_last_to_nexttolast(dep) \
do { \
(dep)->de_fc[FC_NEXTTOLASTFC].fc_frcn = (dep)->de_fc[FC_LASTFC].fc_frcn; \
(dep)->de_fc[FC_NEXTTOLASTFC].fc_fsrcn = (dep)->de_fc[FC_LASTFC].fc_fsrcn; \
} while (0)

/*
* Auxiliary results from an msdosfs_lookup operation
*/
struct msdosfs_lookup_results {
u_long mlr_fndoffset; /* offset of found dir entry */
int mlr_fndcnt; /* number of slots before de_fndoffset */
};

/*
* This is the in memory variant of a dos directory entry. It is usually
* contained within a vnode.
*/
struct denode_key {
u_long dk_dirclust; /* cluster of the directory file containing this entry */
u_long dk_diroffset; /* offset of this entry in the directory cluster */
void *dk_dirgen; /* non zero and unique for unlinked nodes */
};
struct denode {
struct genfs_node de_gnode;
struct vnode *de_vnode; /* addr of vnode we are part of */
struct vnode *de_devvp; /* vnode of blk dev we live on */
u_long de_flag; /* flag bits */
dev_t de_dev; /* device where direntry lives */
struct denode_key de_key;
#define de_dirclust de_key.dk_dirclust
#define de_diroffset de_key.dk_diroffset
#define de_dirgen de_key.dk_dirgen
struct msdosfs_lookup_results de_crap; /* results from lookup */
long de_refcnt; /* reference count */
struct msdosfsmount *de_pmp; /* addr of our mount struct */
struct lockf *de_lockf; /* byte level lock list */
u_char de_Name[12]; /* name, from DOS directory entry */
u_char de_Attributes; /* attributes, from directory entry */
u_char de_CHun; /* Hundredth of second of CTime*/
u_short de_CTime; /* creation time */
u_short de_CDate; /* creation date */
u_short de_ADate; /* access date */
u_short de_MTime; /* modification time */
u_short de_MDate; /* modification date */
u_long de_StartCluster; /* starting cluster of file */
u_long de_FileSize; /* size of file in bytes */
struct fatcache de_fc[FC_SIZE]; /* FAT cache */
};

/*
* Values for the de_flag field of the denode.
*/
#define DE_UPDATE 0x0001 /* Modification time update request. */
#define DE_CREATE 0x0002 /* Creation time update */
#define DE_ACCESS 0x0004 /* Access time update */
#define DE_MODIFIED 0x0008 /* Denode has been modified. */
#define DE_RENAME 0x0010 /* Denode is in the process of being renamed */

/*
* Maximum filename length in Win95
* Note: Must be < sizeof(dirent.d_name)
*/
#define WIN_MAXLEN 255

/* Maximum size of a file on a FAT filesystem */
#define MSDOSFS_FILESIZE_MAX 0xFFFFFFFFLL

/*
* Transfer directory entries between internal and external form.
* dep is a struct denode * (internal form),
* dp is a struct direntry * (external form).
*/
#define DE_INTERNALIZE32(dep, dp) \
((dep)->de_StartCluster |= getushort((dp)->deHighClust) << 16)
#define DE_INTERNALIZE(dep, dp) \
(memcpy((dep)->de_Name, (dp)->deName, 8), \
memcpy((dep)->de_Name+8, (dp)->deExtension, 3),\
(dep)->de_Attributes = (dp)->deAttributes, \
(dep)->de_CHun = (dp)->deCHundredth, \
(dep)->de_CTime = getushort((dp)->deCTime), \
(dep)->de_CDate = getushort((dp)->deCDate), \
(dep)->de_ADate = getushort((dp)->deADate), \
(dep)->de_MTime = getushort((dp)->deMTime), \
(dep)->de_MDate = getushort((dp)->deMDate), \
(dep)->de_StartCluster = getushort((dp)->deStartCluster), \
(dep)->de_FileSize = getulong((dp)->deFileSize), \
(FAT32((dep)->de_pmp) ? DE_INTERNALIZE32((dep), (dp)) : 0))

#define DE_EXTERNALIZE32(dp, dep) \
putushort((dp)->deHighClust, (dep)->de_StartCluster >> 16)
#define DE_EXTERNALIZE16(dp, dep) \
putushort((dp)->deHighClust, 0)
#define DE_EXTERNALIZE(dp, dep) \
(memcpy((dp)->deName, (dep)->de_Name, 8), \
memcpy((dp)->deExtension, (dep)->de_Name+8, 3),\
(dp)->deAttributes = (dep)->de_Attributes, \
(dp)->deCHundredth = (dep)->de_CHun, \
putushort((dp)->deCTime, (dep)->de_CTime), \
putushort((dp)->deCDate, (dep)->de_CDate), \
putushort((dp)->deADate, (dep)->de_ADate), \
putushort((dp)->deMTime, (dep)->de_MTime), \
putushort((dp)->deMDate, (dep)->de_MDate), \
putushort((dp)->deStartCluster, (dep)->de_StartCluster), \
putulong((dp)->deFileSize, \
((dep)->de_Attributes & ATTR_DIRECTORY) ? 0 : (dep)->de_FileSize), \
(FAT32((dep)->de_pmp) ? DE_EXTERNALIZE32((dp), (dep)) : DE_EXTERNALIZE16((dp), (dep))))

#define de_forw de_chain[0]
#define de_back de_chain[1]

#if defined(_KERNEL) || defined(MAKEFS)

#define VTODE(vp) ((struct denode *)(vp)->v_data)
#define DETOV(de) ((de)->de_vnode)

#define DETIMES(dep, acc, mod, cre, gmtoff) \
while ((dep)->de_flag & (DE_UPDATE | DE_CREATE | DE_ACCESS)) \
msdosfs_detimes(dep, acc, mod, cre, gmtoff)

/*
* This overlays the fid structure (see fstypes.h)
*/
struct defid {
u_int16_t defid_len; /* length of structure */
u_int16_t defid_pad; /* force 4-byte alignment */

u_int32_t defid_dirclust; /* cluster this dir entry came from */
u_int32_t defid_dirofs; /* offset of entry within the cluster */
u_int32_t defid_gen; /* generation number */
};

/*
* Prototypes for MSDOSFS vnode operations
*/
int msdosfs_lookup (void *);
int msdosfs_create (void *);
int msdosfs_close (void *);
int msdosfs_access (void *);
int msdosfs_getattr (void *);
int msdosfs_setattr (void *);
int msdosfs_read (void *);
int msdosfs_write (void *);
int msdosfs_fsync (void *);
int msdosfs_remove (void *);
int msdosfs_rename (void *);
int msdosfs_mkdir (void *);
int msdosfs_rmdir (void *);
int msdosfs_readdir (void *);
int msdosfs_inactive (void *);
int msdosfs_reclaim (void *);
int msdosfs_bmap (void *);
int msdosfs_strategy (void *);
int msdosfs_print (void *);
int msdosfs_advlock (void *);
int msdosfs_pathconf (void *);

/*
* Internal service routine prototypes.
*/
struct componentname;
struct direntry;
struct kauth_cred;
int msdosfs_update(struct vnode *, const struct timespec *,
const struct timespec *, int);
int msdosfs_createde(struct denode *, struct denode *,
const struct msdosfs_lookup_results *,
struct denode **, struct componentname *);
int msdosfs_deextend(struct denode *, u_long, struct kauth_cred *);
#ifdef MAKEFS
int msdosfs_deget(struct msdosfsmount *, u_long, u_long, struct denode **);
#else
int msdosfs_deget(struct msdosfsmount *, u_long, u_long, struct vnode **);
#endif
int msdosfs_detrunc(struct denode *, u_long, int, struct kauth_cred *);
int msdosfs_deupdat(struct denode *, int);
int msdosfs_dosdirempty(struct denode *);
int msdosfs_readde(struct denode *, struct buf **, struct direntry **);
int msdosfs_readep(struct msdosfsmount *, u_long, u_long,
struct buf **, struct direntry **);
int msdosfs_removede(struct denode *, struct denode *,
const struct msdosfs_lookup_results *);
int msdosfs_uniqdosname(struct denode *, struct componentname *, u_char *);
int msdosfs_findwin95(struct denode *);
int msdosfs_gop_alloc(struct vnode *, off_t, off_t, int,
struct kauth_cred *);
void msdosfs_gop_markupdate(struct vnode *, int);
void msdosfs_detimes(struct denode *, const struct timespec *,
const struct timespec *, const struct timespec *, int);
int msdosfs_fh_enter(struct msdosfsmount *, uint32_t, uint32_t, uint32_t *);
int msdosfs_fh_remove(struct msdosfsmount *, uint32_t, uint32_t);
int msdosfs_fh_lookup(struct msdosfsmount *, uint32_t, uint32_t,
uint32_t *);
void msdosfs_fh_destroy(struct msdosfsmount *);
#endif /* _KERNEL || MAKEFS */
#endif /* _MSDOSFS_DENODE_H_ */