/*      $NetBSD: ext2fs_dir.h,v 1.23 2024/03/10 17:36:33 christos Exp $ */

/*
* Copyright (c) 1982, 1986, 1989, 1993
*      The Regents of the University of California.  All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* 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. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 THE REGENTS OR CONTRIBUTORS 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.
*
*      @(#)dir.h       8.4 (Berkeley) 8/10/94
* Modified for ext2fs by Manuel Bouyer.
*/

/*
* Copyright (c) 1997 Manuel Bouyer.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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.
*
*      @(#)dir.h       8.4 (Berkeley) 8/10/94
* Modified for ext2fs by Manuel Bouyer.
*/

#ifndef _UFS_EXT2FS_EXT2FS_DIR_H_
#define _UFS_EXT2FS_EXT2FS_DIR_H_

#include <sys/dirent.h>
#include <ufs/ext2fs/ext2fs_dinode.h>

/*
* Theoretically, directories can be more than 2Gb in length, however, in
* practice this seems unlikely. So, we define the type doff_t as a 32-bit
* quantity to keep down the cost of doing lookup on a 32-bit machine.
*/
#define doff_t                  int32_t
#define EXT2FS_MAXDIRSIZE       INT32_MAX

/*
* A directory consists of some number of blocks of e2fs_bsize bytes.
*
* Each block contains some number of directory entry
* structures, which are of variable length.  Each directory entry has
* a struct direct at the front of it, containing its inode number,
* the length of the entry, and the length of the name contained in
* the entry.  These are followed by the name padded to a 4 byte boundary
* with null bytes.  All names are guaranteed null terminated.
* The maximum length of a name in a directory is EXT2FS_MAXNAMLEN.
*
* The macro EXT2FS_DIRSIZ(fmt, dp) gives the amount of space required to
* represent a directory entry.  Free space in a directory is represented by
* entries which have dp->e2d_reclen > DIRSIZ(fmt, dp).  All d2fs_bsize bytes
* in a directory block are claimed by the directory entries.  This
* usually results in the last entry in a directory having a large
* dp->e2d_reclen.  When entries are deleted from a directory, the
* space is returned to the previous entry in the same directory
* block by increasing its dp->e2d_reclen.  If the first entry of
* a directory block is free, then its dp->e2d_ino is set to 0.
* Entries other than the first in a directory do not normally have
* dp->e2d_ino set to 0.
* Ext2 rev 0 has a 16 bits e2d_namlen. For Ext2 vev 1 this has been split
* into a 8 bits e2d_namlen and 8 bits e2d_type (looks like ffs, isnt't it ? :)
* It's safe to use this for rev 0 as well because all ext2 are little-endian.
*/

#define EXT2FS_MAXNAMLEN        255

struct  ext2fs_direct {
       uint32_t e2d_ino;               /* inode number of entry */
       uint16_t e2d_reclen;            /* length of this record */
       uint8_t e2d_namlen;             /* length of string in d_name */
       uint8_t e2d_type;               /* file type */
       char e2d_name[EXT2FS_MAXNAMLEN];/* name with length<=EXT2FS_MAXNAMLEN */
};

enum ext2fs_slotstatus {
       NONE,
       COMPACT,
       FOUND
};

struct ext2fs_searchslot {
       enum ext2fs_slotstatus slotstatus;
       doff_t slotoffset;              /* offset of area with free space */
       int slotsize;                   /* size of area at slotoffset */
       int slotfreespace;              /* amount of space free in slot */
       int slotneeded;                 /* sizeof the entry we are seeking */
};

/* Ext2 directory file types (not the same as FFS. Sigh.) */
#define EXT2_FT_UNKNOWN         0
#define EXT2_FT_REG_FILE        1
#define EXT2_FT_DIR             2
#define EXT2_FT_CHRDEV          3
#define EXT2_FT_BLKDEV          4
#define EXT2_FT_FIFO            5
#define EXT2_FT_SOCK            6
#define EXT2_FT_SYMLINK         7

#define EXT2_FT_MAX             8

#define E2IFTODT(mode)    (((mode) & 0170000) >> 12)

static __inline uint8_t inot2ext2dt(uint16_t) __unused;
static __inline uint8_t
inot2ext2dt(uint16_t type)
{

       switch (type) {
       case E2IFTODT(EXT2_IFIFO):
               return EXT2_FT_FIFO;
       case E2IFTODT(EXT2_IFCHR):
               return EXT2_FT_CHRDEV;
       case E2IFTODT(EXT2_IFDIR):
               return EXT2_FT_DIR;
       case E2IFTODT(EXT2_IFBLK):
               return EXT2_FT_BLKDEV;
       case E2IFTODT(EXT2_IFREG):
               return EXT2_FT_REG_FILE;
       case E2IFTODT(EXT2_IFLNK):
               return EXT2_FT_SYMLINK;
       case E2IFTODT(EXT2_IFSOCK):
               return EXT2_FT_SOCK;
       default:
               return 0;
       }
}

static __inline uint8_t ext2dt2dt(uint8_t) __unused;
static __inline uint8_t
ext2dt2dt(uint8_t type)
{
       switch (type) {
       case EXT2_FT_REG_FILE:
               return DT_REG;
       case EXT2_FT_DIR:
               return DT_DIR;
       case EXT2_FT_CHRDEV:
               return DT_CHR;
       case EXT2_FT_BLKDEV:
               return DT_BLK;
       case EXT2_FT_FIFO:
               return DT_FIFO;
       case EXT2_FT_SOCK:
               return DT_SOCK;
       case EXT2_FT_SYMLINK:
               return DT_LNK;
       default:
               return DT_UNKNOWN;
       }
}

/*
* The EXT2FS_DIRSIZ macro gives the minimum record length which will hold
* the directory entryfor a name len "len" (without the terminating null byte).
* This requires the amount of space in struct direct
* without the d_name field, plus enough space for the name without a
* terminating null byte, rounded up to a 4 byte boundary.
*/
#define EXT2FS_DIRSIZ(len)      roundup2(8 + len, 4)

/*
* Template for manipulating directories.  Should use struct direct's,
* but the name field is EXT2FS_MAXNAMLEN - 1, and this just won't do.
*/
struct ext2fs_dirtemplate {
       uint32_t        dot_ino;
       int16_t         dot_reclen;
       uint8_t         dot_namlen;
       uint8_t         dot_type;
       char            dot_name[4];    /* must be multiple of 4 */
       uint32_t        dotdot_ino;
       int16_t         dotdot_reclen;
       uint8_t         dotdot_namlen;
       uint8_t         dotdot_type;
       char            dotdot_name[4]; /* ditto */
};

/*
* EXT2_DIR_PAD defines the directory entries boundaries
*
* NOTE: It must be a multiple of 4
*/
#define EXT2_DIR_PAD    4
#define EXT2_DIR_ROUND  (EXT2_DIR_PAD - 1)
#define EXT2_DIR_REC_LEN(namelen) \
   (((namelen) + 8 + EXT2_DIR_ROUND) & ~EXT2_DIR_ROUND)

#endif /* !_UFS_EXT2FS_EXT2FS_DIR_H_ */