/*
** The Sleuth Kit 
**
** $Date: 2007/12/20 20:32:38 $
**
** Brian Carrier [carrier@sleuthkit.org]
** Copyright (c) 2003-2008 Brian Carrier.  All rights reserved
**
** TASK
** Copyright (c) 2002 Brian Carrier, @stake Inc.  All rights reserved
** 
*/

/** \file tsk_ext2fs.h
 * Contains the structures and function APIs for EXT2FS file system support.
 */

#ifndef _TSK_EXT2FS_H
#define _TSK_EXT2FS_H

#ifdef __cplusplus
extern "C" {
#endif

    typedef uint32_t EXT2_GRPNUM_T;
#define PRI_EXT2GRP	PRIu32

/*
** Constants
*/
#define EXT2FS_FIRSTINO    1    /* inode 1 contains the bad blocks */
#define EXT2FS_ROOTINO     2    /* location of root directory inode */
#define EXT2FS_NDADDR      12
#define EXT2FS_NIADDR      3
#define EXT2FS_SBOFF       1024
#define EXT2FS_FS_MAGIC    0xef53
#define EXT2FS_MAXNAMLEN	255
#define EXT2FS_MAXPATHLEN	4096
#define EXT2FS_MIN_BLOCK_SIZE	1024
#define EXT2FS_MAX_BLOCK_SIZE	4096
#define EXT2FS_DEV_BSIZE	512

/*
** Super Block
*/
    typedef struct {
        uint8_t s_inodes_count[4];      /* u32 */
        uint8_t s_blocks_count[4];      /* u32 */
        uint8_t s_r_blocks_count[4];
        uint8_t s_free_blocks_count[4]; /* u32 */
        uint8_t s_free_inode_count[4];  /* u32 */
        uint8_t s_first_data_block[4];  /* u32 */
        uint8_t s_log_block_size[4];    /* u32 */
        uint8_t s_log_frag_size[4];     /* s32 */
        uint8_t s_blocks_per_group[4];  /* u32 */
        uint8_t s_frags_per_group[4];   /* u32 */
        uint8_t s_inodes_per_group[4];  /* u32 */
        uint8_t s_mtime[4];     /* u32 *//* mount time */
        uint8_t s_wtime[4];     /* u32 *//* write time */
        uint8_t s_mnt_count[2]; /* u16 *//* mount count */
        uint8_t s_max_mnt_count[2];     /* s16 */
        uint8_t s_magic[2];     /* u16 */
        uint8_t s_state[2];     /* u16 *//* fs state */
        uint8_t s_errors[2];    /* u16 */
        uint8_t s_minor_rev_level[2];   /* u16 */
        uint8_t s_lastcheck[4]; /* u32 */
        uint8_t s_checkinterval[4];     /* u32 */
        uint8_t s_creator_os[4];        /* u32 */
        uint8_t s_rev_level[4]; /* u32 */
        uint8_t s_def_resuid[2];        /* u16 */
        uint8_t s_def_resgid[2];        /* u16 */
        uint8_t s_first_ino[4]; /* u32 */
        uint8_t s_inode_size[2];        /* u16 */
        uint8_t s_block_group_nr[2];    /* u16 */
        uint8_t s_feature_compat[4];    /* u32 */
        uint8_t s_feature_incompat[4];  /* u32 */
        uint8_t s_feature_ro_compat[4]; /* u32 */
        uint8_t s_uuid[16];     /* u8[16] */
        char s_volume_name[16];
        char s_last_mounted[64];
        uint8_t s_algorithm_usage_bitmap[4];    /* u32 */
        uint8_t s_prealloc_blocks;      /* u8 */
        uint8_t s_prealloc_dir_blocks;  /* u8 */
        uint8_t s_padding1[2];  /* u16 */
        uint8_t s_journal_uuid[16];     /* u8[16] */
        uint8_t s_journal_inum[4];      /* u32 */
        uint8_t s_journal_dev[4];       /* u32 */
        uint8_t s_last_orphan[4];       /* u32 */
        uint8_t s_padding[788];
    } ext2fs_sb;

/* File system State Values */
#define EXT2FS_STATE_VALID	0x0001  /* unmounted correctly */
#define EXT2FS_STATE_ERROR	0x0002  /* errors detected */

/* Operating System Codes */
#define EXT2FS_OS_LINUX		0
#define EXT2FS_OS_HURD		1
#define	EXT2FS_OS_MASIX		2
#define EXT2FS_OS_FREEBSD	3
#define EXT2FS_OS_LITES		4

/* Revision Levels */
#define EXT2FS_REV_ORIG		0
#define EXT2FS_REV_DYN		1

/* feature flags */
#define EXT2FS_FEATURE_COMPAT_DIR_PREALLOC	0x0001
#define EXT2FS_FEATURE_COMPAT_IMAGIC_INODES	0x0002
#define EXT2FS_FEATURE_COMPAT_HAS_JOURNAL	0x0004
#define EXT2FS_FEATURE_COMPAT_EXT_ATTR		0x0008
#define EXT2FS_FEATURE_COMPAT_RESIZE_INO	0x0010
#define EXT2FS_FEATURE_COMPAT_DIR_INDEX		0x0020

#define EXT2FS_FEATURE_INCOMPAT_COMPRESSION	0x0001
#define EXT2FS_FEATURE_INCOMPAT_FILETYPE	0x0002
#define EXT2FS_FEATURE_INCOMPAT_RECOVER		0x0004
#define EXT2FS_FEATURE_INCOMPAT_JOURNAL_DEV	0x0008

#define EXT2FS_FEATURE_RO_COMPAT_SPARSE_SUPER	0x0001
#define EXT2FS_FEATURE_RO_COMPAT_LARGE_FILE		0x0002
#define EXT2FS_FEATURE_RO_COMPAT_BTREE_DIR		0x0004



/*
 * Group Descriptor
 */
    typedef struct {
        uint8_t bg_block_bitmap[4];     /* u32: block of blocks bitmap */
        uint8_t bg_inode_bitmap[4];     /* u32: block of inodes bitmap */
        uint8_t bg_inode_table[4];      /* u32: block of inodes table */
        uint8_t bg_free_blocks_count[2];        /* u16: num of free blocks */
        uint8_t bg_free_inodes_count[2];        /* u16: num of free inodes */
        uint8_t bg_used_dirs_count[2];  /* u16: num of use directories  */
        uint8_t f1[14];
    } ext2fs_gd;


/* data address to group number */
#define ext2_dtog_lcl(fsi, fs, d)	\
	(EXT2_GRPNUM_T)(((d) - tsk_getu32(fsi->endian, fs->s_first_data_block)) / \
	tsk_getu32(fsi->endian, fs->s_blocks_per_group))


/* first fragment of group */
#define ext2_cgbase_lcl(fsi, fs, c)	\
	((TSK_DADDR_T)((tsk_getu32(fsi->endian, fs->s_blocks_per_group) * (c)) + \
	tsk_getu32(fsi->endian, fs->s_first_data_block)))


/*
 * Inode
 */
    typedef struct {
        uint8_t i_mode[2];      /* u16 */
        uint8_t i_uid[2];       /* u16 */
        uint8_t i_size[4];      /* u32 */
        uint8_t i_atime[4];     /* u32 */
        uint8_t i_ctime[4];     /* u32 */
        uint8_t i_mtime[4];     /* u32 */
        uint8_t i_dtime[4];     /* u32 */
        uint8_t i_gid[2];       /* u16 */
        uint8_t i_nlink[2];     /* u16 */
        uint8_t i_nblk[4];
        uint8_t i_flags[4];
        uint8_t i_f5[4];
        uint8_t i_block[15][4]; /*s32 */
        uint8_t i_generation[4];
        uint8_t i_file_acl[4];
        uint8_t i_size_high[4]; /* u32 - also i_dir_acl for non-regular  */
        uint8_t i_faddr[4];
        uint8_t i_frag;
        uint8_t i_fsize;
        uint8_t f1[2];
        uint8_t i_uid_high[2];
        uint8_t i_gid_high[2];
        uint8_t f7[4];
    } ext2fs_inode;

/* MODE */
#define EXT2_IN_FMT  0017000
#define EXT2_IN_SOCK 0140000
#define EXT2_IN_LNK  0120000
#define EXT2_IN_REG  0100000
#define EXT2_IN_BLK  0060000
#define EXT2_IN_DIR  0040000
#define EXT2_IN_CHR  0020000
#define EXT2_IN_FIFO  0010000

#define EXT2_IN_SECDEL 		0x00000001      /* Secure deletion */
#define EXT2_IN_UNRM 		0x00000002      /* Undelete */
#define EXT2_IN_COMP 		0x00000004      /* Compress file */
#define EXT2_IN_SYNC		0x00000008      /* Synchronous updates */
#define EXT2_IN_IMM		 	0x00000010      /* Immutable file */
#define EXT2_IN_APPEND 		0x00000020      /* writes to file may only append */
#define EXT2_IN_NODUMP 		0x00000040      /* do not dump file */
#define EXT2_IN_NOA		 	0x00000080      /* do not update atime */



/*
 * directory entries
 */
    typedef struct {
        uint8_t inode[4];       /* u32 */
        uint8_t rec_len[2];     /* u16 */
        uint8_t name_len[2];    /* u16 */
        char name[EXT2FS_MAXNAMLEN];
    } ext2fs_dentry1;

/* new structure starting at 2.2 */
    typedef struct {
        uint8_t inode[4];       /* u32 */
        uint8_t rec_len[2];     /* u16 */
        uint8_t name_len;
        uint8_t type;
        char name[EXT2FS_MAXNAMLEN];
    } ext2fs_dentry2;

#define EXT2FS_DIRSIZ_lcl(len) \
    ((len + 8 + 3) & ~(3))


/* Ext2 directory file types (not the same as FFS. Sigh. */
#define EXT2_DE_UNKNOWN         0
#define EXT2_DE_REG_FILE        1
#define EXT2_DE_DIR             2
#define EXT2_DE_CHRDEV          3
#define EXT2_DE_BLKDEV          4
#define EXT2_DE_FIFO            5
#define EXT2_DE_SOCK            6
#define EXT2_DE_SYMLINK         7
#define EXT2_DE_MAX             8


#define EXT2_DE_V1	1
#define EXT2_DE_V2	2




/* Extended Attributes
 */

#define EXT2_EA_MAGIC	0xEA020000

    typedef struct {
        uint8_t magic[4];
        uint8_t refcount[4];
        uint8_t blocks[4];
        uint8_t hash[4];
        uint8_t f1[16];
        uint8_t entry;
    } ext2fs_ea_header;


#define EXT2_EA_IDX_USER                   1
#define EXT2_EA_IDX_POSIX_ACL_ACCESS       2
#define EXT2_EA_IDX_POSIX_ACL_DEFAULT      3
#define EXT2_EA_IDX_TRUSTED                4
#define EXT2_EA_IDX_LUSTRE                 5
#define EXT2_EA_IDX_SECURITY               6

/* Entries follow the header and are aligned to 4-byte boundaries 
 * the value of the attribute is stored at the bottom of the block 
 */
    typedef struct {
        uint8_t nlen;
        uint8_t nidx;
        uint8_t val_off[2];
        uint8_t val_blk[4];
        uint8_t val_size[4];
        uint8_t hash[4];
        uint8_t name;
    } ext2fs_ea_entry;

#define EXT2_EA_LEN(nlen) \
	((((nlen) + 19 ) / 4) * 4)


    typedef struct {
        uint8_t ver[4];
    } ext2fs_pos_acl_head;


#define EXT2_PACL_TAG_USERO	0x01
#define EXT2_PACL_TAG_USER	0x02
#define EXT2_PACL_TAG_GRPO	0x04
#define EXT2_PACL_TAG_GRP	0x08
#define EXT2_PACL_TAG_MASK	0x10
#define EXT2_PACL_TAG_OTHER	0x20


#define EXT2_PACL_PERM_EXEC	0x01
#define EXT2_PACL_PERM_WRITE	0x02
#define EXT2_PACL_PERM_READ	0x04


    typedef struct {
        uint8_t tag[2];
        uint8_t perm[2];
    } ext2fs_pos_acl_entry_sh;

    typedef struct {
        uint8_t tag[2];
        uint8_t perm[2];
        uint8_t id[4];
    } ext2fs_pos_acl_entry_lo;




/************** JOURNAL ******************/

/* These values are always in big endian */

#define EXT2_JMAGIC	0xC03b3998

    typedef struct {
        uint8_t magic[4];
        uint8_t entrytype[4];
        uint8_t entryseq[4];    /* sequence of this entry */
        uint8_t bsize[4];       /* size of block */

        uint8_t num_blk[4];     /* num of blks in journal */
        uint8_t first_blk[4];   /* bl where log starts */
        uint8_t start_seq[4];   /* first commit ID in log */
        uint8_t start_blk[4];   /* journ blk for 1st valid entry */

        uint8_t j_errno[4];     /* signed error number */

/* the rest are not valid for v1 sb */
        uint8_t feature_compat[4];
        uint8_t feature_incompat[4];
        uint8_t feature_ro_incompat[4];
        uint8_t uuid[16];
        uint8_t num_fs[4];      /* num of fs sharing log */
        uint8_t dynsuper[4];    /* fs block of sb copy */
        uint8_t max_trans[4];   /* limit of blk per trans */
        uint8_t max_trans_data[4];      /* limit of data blocks per */
        uint8_t reserved[176];
        uint8_t id_fs[16][48];  /* Ids of fs sharing log */
    } ext2fs_journ_sb;


#define EXT2_J_ETYPE_DESC	1       /* descriptor block */
#define EXT2_J_ETYPE_COM	2       /* commit */
#define EXT2_J_ETYPE_SB1	3       /* super block v1 */
#define EXT2_J_ETYPE_SB2	4       /* sb v2 */
#define EXT2_J_ETYPE_REV	5       /* revoke */


/* Header that is used for all structures */
    typedef struct {
        uint8_t magic[4];
        uint8_t entry_type[4];
        uint8_t entry_seq[4];
    } ext2fs_journ_head;


/* dentry flags */
#define EXT2_J_DENTRY_ESC	1       /* The orig block starts with magic */
#define EXT2_J_DENTRY_SAMEID	2       /* Entry is for same id, so do not skip 16 ahead */
#define EXT2_J_DENTRY_DEL	4       /* not currently used in src */
#define EXT2_J_DENTRY_LAST	8       /* Last tag */

/* Entry in the descriptor table */
    typedef struct {
        uint8_t fs_blk[4];
        uint8_t flag[4];
    } ext2fs_journ_dentry;


/* Journal Info */
    typedef struct {

        TSK_FS_INODE *fs_inode;
        TSK_INUM_T j_inum;

        uint32_t bsize;
        TSK_DADDR_T first_block;
        TSK_DADDR_T last_block;

        uint32_t start_seq;
        TSK_DADDR_T start_blk;

    } EXT2FS_JINFO;



    /*
     * Structure of an ext2fs file system handle.
     */
    typedef struct {
        TSK_FS_INFO fs_info;    /* super class */
        ext2fs_sb *fs;          /* super block */

        ext2fs_gd *grp_buf;     /* cached group descriptor */
        EXT2_GRPNUM_T grp_num;  /* cached group number */

        uint8_t *bmap_buf;        /* cached block allocation bitmap */
        EXT2_GRPNUM_T bmap_grp_num;     /* cached block bitmap nr */

        uint8_t *imap_buf;        /* cached inode allocation bitmap */
        EXT2_GRPNUM_T imap_grp_num;     /* cached inode bitmap nr */

        ext2fs_inode *dino_buf; /* cached disk inode */
        TSK_INUM_T dino_inum;       /* cached inode number */

        TSK_OFF_T groups_offset;    /* offset to first group desc */
        EXT2_GRPNUM_T groups_count;     /* nr of descriptor group blocks */
        uint8_t deentry_type;   /* v1 or v2 of dentry */
        uint16_t inode_size;    /* size of each inode */
        TSK_DADDR_T first_data_block;

        EXT2FS_JINFO *jinfo;
    } EXT2FS_INFO;

    extern uint8_t ext2fs_dent_walk(TSK_FS_INFO *, TSK_INUM_T,
        TSK_FS_DENT_FLAG_ENUM, TSK_FS_DENT_TYPE_WALK_CB, void *);
    extern uint8_t ext2fs_jentry_walk(TSK_FS_INFO *, int,
        TSK_FS_JENTRY_WALK_CB, void *);
    extern uint8_t ext2fs_jblk_walk(TSK_FS_INFO *, TSK_DADDR_T, TSK_DADDR_T, int,
        TSK_FS_JBLK_WALK_CB, void *);
    extern uint8_t ext2fs_jopen(TSK_FS_INFO *, TSK_INUM_T);

#ifdef __cplusplus
}
#endif
#endif
