/*
** The Sleuth Kit 
**
** Brian Carrier [carrier <at> sleuthkit [dot] org]
** Copyright (c) 2003-2008 Brian Carrier.  All rights reserved
**
** TASK
** Copyright (c) 2002 @stake Inc.  All rights reserved
**
** This software is distributed under the Common Public License 1.0
**
*/

/*
 * Contains the structures and function APIs for FATFS file system support.
 */


#ifndef _TSK_FATFS_H
#define _TSK_FATFS_H

#ifdef __cplusplus
extern "C" {
#endif

/*
** Constants
*/
#define FATFS_FIRSTINO	2
#define FATFS_ROOTINO	2       /* location of root directory inode */
#define FATFS_FIRST_NORMINO 3

    // special files go at end of inode list (before $OrphanFiles)
#define FATFS_NUM_SPECFILE  4   // includes MBR, FAT1, FAT2, and Orphans

#define FATFS_MBRINO(fs_info) \
    (TSK_FS_ORPHANDIR_INUM(fs_info) - 3)        // inode for master boot record "special file"
#define FATFS_MBRNAME   "$MBR"

#define FATFS_FAT1INO(fs_info) \
    (TSK_FS_ORPHANDIR_INUM(fs_info) - 2)        // inode for FAT1 "special file"
#define FATFS_FAT1NAME  "$FAT1"

#define FATFS_FAT2INO(fs_info) \
    (TSK_FS_ORPHANDIR_INUM(fs_info) - 1)        // inode for FAT2 "special file"
#define FATFS_FAT2NAME  "$FAT2"




#define FATFS_DEV_BSIZE 512
#define FATFS_SBOFF		0
#define FATFS_FS_MAGIC	0xaa55
#define FATFS_MAXNAMLEN	256
#define FATFS_MAXNAMLEN_UTF8	1024
#define FATFS_FILE_CONTENT_LEN sizeof(TSK_DADDR_T)      // we will store the starting cluster

/* size of FAT to read into FATFS_INFO each time */
/* This must be at least 1024 bytes or else fat12 will get messed up */
#define FAT_CACHE_N		4       // number of caches
#define FAT_CACHE_B		4096
#define FAT_CACHE_S		8       // number of sectors in cache

/* MASK values for FAT entries */
#define FATFS_12_MASK	0x00000fff
#define FATFS_16_MASK	0x0000ffff
#define FATFS_32_MASK	0x0fffffff

/* Constants for the FAT entry */
#define FATFS_UNALLOC	0
#define FATFS_BAD		0x0ffffff7
#define FATFS_EOFS		0x0ffffff8
#define FATFS_EOFE		0x0fffffff



/* macro to identify if the FAT value is End of File
 * returns 1 if it is and 0 if it is not 
 */
#define FATFS_ISEOF(val, mask)	\
	((val >= (FATFS_EOFS & mask)) && (val <= (FATFS_EOFE)))


#define FATFS_ISBAD(val, mask) \
	((val) == (FATFS_BAD & mask))


#define FATFS_CLUST_2_SECT(fatfs, c)	\
	(TSK_DADDR_T)(fatfs->firstclustsect + ((((c) & fatfs->mask) - 2) * fatfs->csize))

#define FATFS_SECT_2_CLUST(fatfs, s)	\
	(TSK_DADDR_T)(2 + ((s)  - fatfs->firstclustsect) / fatfs->csize)



/* given an inode address, determine in which sector it is located
 * i must be larger than 3 (2 is the root and it doesn't have a sector)
 */
#define FATFS_INODE_2_SECT(fatfs, i)    \
    (TSK_DADDR_T)((i - FATFS_FIRST_NORMINO)/(fatfs->dentry_cnt_se) + fatfs->firstdatasect)

#define FATFS_INODE_2_OFF(fatfs, i)     \
    (size_t)(((i - FATFS_FIRST_NORMINO) % fatfs->dentry_cnt_se) * sizeof(fatfs_dentry))



/* given a sector IN THE DATA AREA, return the base inode for it */
#define FATFS_SECT_2_INODE(fatfs, s)    \
    (TSK_INUM_T)((s - fatfs->firstdatasect) * fatfs->dentry_cnt_se + FATFS_FIRST_NORMINO)



/*
 * Boot Sector Structure for TSK_FS_INFO_TYPE_FAT_12, TSK_FS_INFO_TYPE_FAT_16, and TSK_FS_INFO_TYPE_FAT_32
 */
    typedef struct {
        uint8_t f1[3];
        char oemname[8];
        uint8_t ssize[2];       /* sector size in bytes */
        uint8_t csize;          /* cluster size in sectors */
        uint8_t reserved[2];    /* number of reserved sectors for boot sectors */
        uint8_t numfat;         /* Number of FATs */
        uint8_t numroot[2];     /* Number of Root dentries */
        uint8_t sectors16[2];   /* number of sectors in FS */
        uint8_t f2[1];
        uint8_t sectperfat16[2];        /* size of FAT */
        uint8_t f3[4];
        uint8_t prevsect[4];    /* number of sectors before FS partition */
        uint8_t sectors32[4];   /* 32-bit value of number of FS sectors */

        /* The following are different for fat12/fat16 and fat32 */
        union {
            struct {
                uint8_t f5[3];
                uint8_t vol_id[4];
                uint8_t vol_lab[11];
                uint8_t fs_type[8];
                uint8_t f6[448];
            } f16;
            struct {
                uint8_t sectperfat32[4];
                uint8_t ext_flag[2];
                uint8_t fs_ver[2];
                uint8_t rootclust[4];   /* cluster where root directory is stored */
                uint8_t fsinfo[2];      /* TSK_FS_INFO Location */
                uint8_t bs_backup[2];   /* sector of backup of boot sector */
                uint8_t f5[12];
                uint8_t drvnum;
                uint8_t f6[2];
                uint8_t vol_id[4];
                uint8_t vol_lab[11];
                uint8_t fs_type[8];
                uint8_t f7[420];
            } f32;
        } a;

        uint8_t magic[2];       /* MAGIC for all versions */

    } fatfs_sb;

    typedef struct {
        uint8_t magic1[4];      /* 41615252 */
        uint8_t f1[480];
        uint8_t magic2[4];      /* 61417272 */
        uint8_t freecnt[4];     /* free clusters 0xfffffffff if unknown */
        uint8_t nextfree[4];    /* next free cluster */
        uint8_t f2[12];
        uint8_t magic3[4];      /* AA550000 */
    } fatfs_fsinfo;



/* directory entry short name structure */
    typedef struct {
        uint8_t name[8];
        uint8_t ext[3];
        uint8_t attrib;
        uint8_t lowercase;
        uint8_t ctimeten;       /* create times */
        uint8_t ctime[2];
        uint8_t cdate[2];
        uint8_t adate[2];       /* access time */
        uint8_t highclust[2];
        uint8_t wtime[2];       /* last write time */
        uint8_t wdate[2];
        uint8_t startclust[2];
        uint8_t size[4];
    } fatfs_dentry;


/* Macro to combine the upper and lower 2-byte parts of the starting
 * cluster 
 */
#define FATFS_DENTRY_CLUST(fsi, de)	\
	(TSK_DADDR_T)((tsk_getu16(fsi->endian, de->startclust)) | (tsk_getu16(fsi->endian, de->highclust)<<16))

/* constants for first byte of name[] */
#define FATFS_SLOT_EMPTY	0x00
#define FATFS_SLOT_E5		0x05    /* actual value is 0xe5 */
#define FATFS_SLOT_DELETED	0xe5

/* 
 *Return 1 if c is an valid charactor for a short file name 
 *
 * NOTE: 0x05 is allowed in name[0], and 0x2e (".") is allowed for name[0]
 * and name[1] and 0xe5 is allowed for name[0]
 */

#define FATFS_IS_83_NAME(c)		\
	((((c) < 0x20) || \
	  ((c) == 0x22) || \
	  (((c) >= 0x2a) && ((c) <= 0x2c)) || \
	  ((c) == 0x2e) || \
	  ((c) == 0x2f) || \
	  (((c) >= 0x3a) && ((c) <= 0x3f)) || \
	  (((c) >= 0x5b) && ((c) <= 0x5d)) || \
	  ((c) == 0x7c)) == 0)

// extensions are to be ascii / latin
#define FATFS_IS_83_EXT(c)		\
    (FATFS_IS_83_NAME((c)) && ((c) < 0x7f))



/* flags for attributes field */
#define FATFS_ATTR_NORMAL	0x00    /* normal file */
#define FATFS_ATTR_READONLY	0x01    /* file is readonly */
#define FATFS_ATTR_HIDDEN	0x02    /* file is hidden */
#define FATFS_ATTR_SYSTEM	0x04    /* file is a system file */
#define FATFS_ATTR_VOLUME	0x08    /* entry is a volume label */
#define FATFS_ATTR_DIRECTORY	0x10    /* entry is a directory name */
#define FATFS_ATTR_ARCHIVE	0x20    /* file is new or modified */
#define FATFS_ATTR_LFN		0x0f    /* A long file name entry */
#define FATFS_ATTR_ALL		0x3f    /* all flags set */

/* flags for lowercase field */
#define FATFS_CASE_LOWER_BASE	0x08    /* base is lower case */
#define FATFS_CASE_LOWER_EXT	0x10    /* extension is lower case */
#define FATFS_CASE_LOWER_ALL	0x18    /* both are lower */

#define FATFS_SEC_MASK		0x1f    /* number of seconds div by 2 */
#define FATFS_SEC_SHIFT		0
#define FATFS_SEC_MIN		0
#define FATFS_SEC_MAX		30
#define FATFS_MIN_MASK		0x7e0   /* number of minutes 0-59 */
#define FATFS_MIN_SHIFT		5
#define FATFS_MIN_MIN		0
#define FATFS_MIN_MAX		59
#define FATFS_HOUR_MASK		0xf800  /* number of hours 0-23 */
#define FATFS_HOUR_SHIFT	11
#define FATFS_HOUR_MIN		0
#define FATFS_HOUR_MAX		23

/* return 1 if x is a valid FAT time */
#define FATFS_ISTIME(x)	\
	(((((x & FATFS_SEC_MASK) >> FATFS_SEC_SHIFT) > FATFS_SEC_MAX) || \
	  (((x & FATFS_MIN_MASK) >> FATFS_MIN_SHIFT) > FATFS_MIN_MAX) || \
	  (((x & FATFS_HOUR_MASK) >> FATFS_HOUR_SHIFT) > FATFS_HOUR_MAX) ) == 0)

#define FATFS_DAY_MASK		0x1f    /* day of month 1-31 */
#define FATFS_DAY_SHIFT		0
#define FATFS_DAY_MIN		1
#define FATFS_DAY_MAX		31
#define FATFS_MON_MASK		0x1e0   /* month 1-12 */
#define FATFS_MON_SHIFT		5
#define FATFS_MON_MIN		1
#define FATFS_MON_MAX		12
#define FATFS_YEAR_MASK		0xfe00  /* year, from 1980 0-127 */
#define FATFS_YEAR_SHIFT	9
#define FATFS_YEAR_MIN		0
#define FATFS_YEAR_MAX		127

/* return 1 if x is a valid FAT date */
#define FATFS_ISDATE(x)	\
	 (((((x & FATFS_DAY_MASK) >> FATFS_DAY_SHIFT) > FATFS_DAY_MAX) || \
	   (((x & FATFS_DAY_MASK) >> FATFS_DAY_SHIFT) < FATFS_DAY_MIN) || \
	   (((x & FATFS_MON_MASK) >> FATFS_MON_SHIFT) > FATFS_MON_MAX) || \
	   (((x & FATFS_MON_MASK) >> FATFS_MON_SHIFT) < FATFS_MON_MIN) || \
	   (((x & FATFS_YEAR_MASK) >> FATFS_YEAR_SHIFT) > FATFS_YEAR_MAX) ) == 0)

/* 
 * Long file name support for windows 
 *
 * Contents of this are in UNICODE, not ASCII 
 */
    typedef struct {
        uint8_t seq;
        uint8_t part1[10];
        uint8_t attributes;
        uint8_t reserved1;
        uint8_t chksum;
        uint8_t part2[12];
        uint8_t reserved2[2];
        uint8_t part3[4];
    } fatfs_dentry_lfn;

/* flags for seq field */
#define FATFS_LFN_SEQ_FIRST	0x40    /* This bit is set for the first lfn entry */
#define FATFS_LFN_SEQ_MASK	0x3f    /* These bits are a mask for the decreasing
                                         * sequence number for the entries */

/* internal FATFS_INFO structure */
    typedef struct {
        TSK_FS_INFO fs_info;    /* super class */
        //TSK_DATA_BUF *table;      /* cached section of file allocation table */

        /* FAT cache */
        char fatc_buf[FAT_CACHE_N][FAT_CACHE_B];
        TSK_DADDR_T fatc_addr[FAT_CACHE_N];
        uint8_t fatc_ttl[FAT_CACHE_N];  // ttl of 0 means is not in use


        char *dinodes;          /* cluster size buffer of inode list */
        fatfs_sb *sb;

        fatfs_dentry *dep;


        /* FIrst sector of FAT */
        TSK_DADDR_T firstfatsect;

        /* First sector after FAT  - For TSK_FS_INFO_TYPE_FAT_12 and TSK_FS_INFO_TYPE_FAT_16, this is where the
         * root directory entries are.  For TSK_FS_INFO_TYPE_FAT_32, this is the the first 
         * cluster */
        TSK_DADDR_T firstdatasect;

        /* The sector number were cluster 2 (the first one) is
         * for TSK_FS_INFO_TYPE_FAT_32, it will be the same as firstdatasect, but for TSK_FS_INFO_TYPE_FAT_12 & 16
         * it will be the first sector after the Root directory  */
        TSK_DADDR_T firstclustsect;

        /* size of data area in clusters, starting at firstdatasect */
        TSK_DADDR_T clustcnt;

        TSK_DADDR_T lastclust;

        /* sector where the root directory is located */
        TSK_DADDR_T rootsect;

        uint32_t dentry_cnt_se; /* max number of dentries per sector */
        uint32_t dentry_cnt_cl; /* max number of dentries per cluster */

        uint16_t ssize;         /* size of sectors in bytes */
        uint16_t ssize_sh;      /* power of 2 for size of sectors */
        uint8_t csize;          /* size of clusters in sectors */
        //uint16_t      reserved;       /* number of reserved sectors */
        uint8_t numfat;         /* number of fat tables */
        uint32_t sectperfat;    /* sectors per fat table */
        uint16_t numroot;       /* number of 32-byte dentries in root dir */
        uint32_t mask;          /* the mask to use for the sectors */

        TSK_INUM_T *dir_buf;    // array that holds inode address of directories
        TSK_INUM_T *par_buf;    // array that holds parent directory address of corresponding dir_buf entry
        size_t dir_buf_size;    // number of entries in both dif_buf and par_buf
        size_t dir_buf_next;    // index to the next place to store an address in dir_buf and par_buf
    } FATFS_INFO;


    extern int8_t fatfs_is_sectalloc(FATFS_INFO *, TSK_DADDR_T);
    extern int8_t fatfs_is_clustalloc(FATFS_INFO * fatfs,
        TSK_DADDR_T clust);

    extern uint8_t fatfs_isdentry(FATFS_INFO *, fatfs_dentry *);
    extern uint8_t fatfs_make_root(FATFS_INFO *, TSK_FS_META *);
    extern TSK_RETVAL_ENUM fatfs_dinode_copy(FATFS_INFO *, TSK_FS_META *,
        fatfs_dentry *, TSK_DADDR_T, TSK_INUM_T);

    extern uint8_t fatfs_inode_lookup(TSK_FS_INFO * fs,
        TSK_FS_FILE * a_fs_file, TSK_INUM_T inum);
    extern uint8_t fatfs_inode_walk(TSK_FS_INFO * fs,
        TSK_INUM_T start_inum, TSK_INUM_T end_inum,
        TSK_FS_META_FLAG_ENUM a_flags, TSK_FS_META_WALK_CB a_action,
        void *a_ptr);
    extern uint8_t fatfs_make_data_run(TSK_FS_FILE * a_fs_file);

    extern uint8_t fatfs_getFAT(FATFS_INFO * fatfs, TSK_DADDR_T clust,
        TSK_DADDR_T * value);

    extern TSK_RETVAL_ENUM
        fatfs_dir_open_meta(TSK_FS_INFO * a_fs, TSK_FS_DIR ** a_fs_dir,
        TSK_INUM_T a_addr);


#ifdef __cplusplus
}
#endif
#endif
