root/fs/squashfs/squashfs_fs.h
/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef SQUASHFS_FS
#define SQUASHFS_FS
/*
 * Squashfs
 *
 * Copyright (c) 2002, 2003, 2004, 2005, 2006, 2007, 2008
 * Phillip Lougher <phillip@squashfs.org.uk>
 *
 * squashfs_fs.h
 */

#define SQUASHFS_CACHED_FRAGMENTS       CONFIG_SQUASHFS_FRAGMENT_CACHE_SIZE
#define SQUASHFS_MAJOR                  4
#define SQUASHFS_MINOR                  0
#define SQUASHFS_START                  0

/* size of metadata (inode and directory) blocks */
#define SQUASHFS_METADATA_SIZE          8192
#define SQUASHFS_BLOCK_OFFSET           2

/* default size of block device I/O */
#ifdef CONFIG_SQUASHFS_4K_DEVBLK_SIZE
#define SQUASHFS_DEVBLK_SIZE 4096
#else
#define SQUASHFS_DEVBLK_SIZE 1024
#endif

#define SQUASHFS_FILE_MAX_SIZE          1048576
#define SQUASHFS_FILE_MAX_LOG           20

/* Max length of filename (not 255) */
#define SQUASHFS_NAME_LEN               256

/* Max value for directory header count*/
#define SQUASHFS_DIR_COUNT              256

#define SQUASHFS_INVALID_FRAG           (0xffffffffU)
#define SQUASHFS_INVALID_XATTR          (0xffffffffU)
#define SQUASHFS_INVALID_BLK            (-1LL)

/* Filesystem flags */
#define SQUASHFS_NOI                    0
#define SQUASHFS_NOD                    1
#define SQUASHFS_NOF                    3
#define SQUASHFS_NO_FRAG                4
#define SQUASHFS_ALWAYS_FRAG            5
#define SQUASHFS_DUPLICATE              6
#define SQUASHFS_EXPORT                 7
#define SQUASHFS_COMP_OPT               10

#define SQUASHFS_BIT(flag, bit)         ((flag >> bit) & 1)

#define SQUASHFS_UNCOMPRESSED_INODES(flags)     SQUASHFS_BIT(flags, \
                                                SQUASHFS_NOI)

#define SQUASHFS_UNCOMPRESSED_DATA(flags)       SQUASHFS_BIT(flags, \
                                                SQUASHFS_NOD)

#define SQUASHFS_UNCOMPRESSED_FRAGMENTS(flags)  SQUASHFS_BIT(flags, \
                                                SQUASHFS_NOF)

#define SQUASHFS_NO_FRAGMENTS(flags)            SQUASHFS_BIT(flags, \
                                                SQUASHFS_NO_FRAG)

#define SQUASHFS_ALWAYS_FRAGMENTS(flags)        SQUASHFS_BIT(flags, \
                                                SQUASHFS_ALWAYS_FRAG)

#define SQUASHFS_DUPLICATES(flags)              SQUASHFS_BIT(flags, \
                                                SQUASHFS_DUPLICATE)

#define SQUASHFS_EXPORTABLE(flags)              SQUASHFS_BIT(flags, \
                                                SQUASHFS_EXPORT)

#define SQUASHFS_COMP_OPTS(flags)               SQUASHFS_BIT(flags, \
                                                SQUASHFS_COMP_OPT)

/* Inode types including extended types */
#define SQUASHFS_DIR_TYPE               1
#define SQUASHFS_REG_TYPE               2
#define SQUASHFS_SYMLINK_TYPE           3
#define SQUASHFS_BLKDEV_TYPE            4
#define SQUASHFS_CHRDEV_TYPE            5
#define SQUASHFS_FIFO_TYPE              6
#define SQUASHFS_SOCKET_TYPE            7
#define SQUASHFS_LDIR_TYPE              8
#define SQUASHFS_LREG_TYPE              9
#define SQUASHFS_LSYMLINK_TYPE          10
#define SQUASHFS_LBLKDEV_TYPE           11
#define SQUASHFS_LCHRDEV_TYPE           12
#define SQUASHFS_LFIFO_TYPE             13
#define SQUASHFS_LSOCKET_TYPE           14

/* Max type value stored in directory entry */
#define SQUASHFS_MAX_DIR_TYPE           7

/* Xattr types */
#define SQUASHFS_XATTR_USER             0
#define SQUASHFS_XATTR_TRUSTED          1
#define SQUASHFS_XATTR_SECURITY         2
#define SQUASHFS_XATTR_VALUE_OOL        256
#define SQUASHFS_XATTR_PREFIX_MASK      0xff

/* Flag whether block is compressed or uncompressed, bit is set if block is
 * uncompressed */
#define SQUASHFS_COMPRESSED_BIT         (1 << 15)

#define SQUASHFS_COMPRESSED_SIZE(B)     (((B) & ~SQUASHFS_COMPRESSED_BIT) ? \
                (B) & ~SQUASHFS_COMPRESSED_BIT :  SQUASHFS_COMPRESSED_BIT)

#define SQUASHFS_COMPRESSED(B)          (!((B) & SQUASHFS_COMPRESSED_BIT))

#define SQUASHFS_COMPRESSED_BIT_BLOCK   (1 << 24)

#define SQUASHFS_COMPRESSED_SIZE_BLOCK(B)       ((B) & \
                                                ~SQUASHFS_COMPRESSED_BIT_BLOCK)

#define SQUASHFS_COMPRESSED_BLOCK(B)    (!((B) & SQUASHFS_COMPRESSED_BIT_BLOCK))

static inline int squashfs_block_size(__le32 raw)
{
        u32 size = le32_to_cpu(raw);
        return (size >> 25) ? -EIO : size;
}

/*
 * Inode number ops.  Inodes consist of a compressed block number, and an
 * uncompressed offset within that block
 */
#define SQUASHFS_INODE_BLK(A)           ((unsigned int) ((A) >> 16))

#define SQUASHFS_INODE_OFFSET(A)        ((unsigned int) ((A) & 0xffff))

#define SQUASHFS_MKINODE(A, B)          ((long long)(((long long) (A)\
                                        << 16) + (B)))

/* fragment and fragment table defines */
#define SQUASHFS_FRAGMENT_BYTES(A)      \
                                ((A) * sizeof(struct squashfs_fragment_entry))

#define SQUASHFS_FRAGMENT_INDEX(A)      (SQUASHFS_FRAGMENT_BYTES(A) / \
                                        SQUASHFS_METADATA_SIZE)

#define SQUASHFS_FRAGMENT_INDEX_OFFSET(A)       (SQUASHFS_FRAGMENT_BYTES(A) % \
                                                SQUASHFS_METADATA_SIZE)

#define SQUASHFS_FRAGMENT_INDEXES(A)    ((SQUASHFS_FRAGMENT_BYTES(A) + \
                                        SQUASHFS_METADATA_SIZE - 1) / \
                                        SQUASHFS_METADATA_SIZE)

#define SQUASHFS_FRAGMENT_INDEX_BYTES(A)        (SQUASHFS_FRAGMENT_INDEXES(A) *\
                                                sizeof(u64))

/* inode lookup table defines */
#define SQUASHFS_LOOKUP_BYTES(A)        ((A) * sizeof(u64))

#define SQUASHFS_LOOKUP_BLOCK(A)        (SQUASHFS_LOOKUP_BYTES(A) / \
                                        SQUASHFS_METADATA_SIZE)

#define SQUASHFS_LOOKUP_BLOCK_OFFSET(A) (SQUASHFS_LOOKUP_BYTES(A) % \
                                        SQUASHFS_METADATA_SIZE)

#define SQUASHFS_LOOKUP_BLOCKS(A)       ((SQUASHFS_LOOKUP_BYTES(A) + \
                                        SQUASHFS_METADATA_SIZE - 1) / \
                                        SQUASHFS_METADATA_SIZE)

#define SQUASHFS_LOOKUP_BLOCK_BYTES(A)  (SQUASHFS_LOOKUP_BLOCKS(A) *\
                                        sizeof(u64))

/* uid/gid lookup table defines */
#define SQUASHFS_ID_BYTES(A)            ((A) * sizeof(unsigned int))

#define SQUASHFS_ID_BLOCK(A)            (SQUASHFS_ID_BYTES(A) / \
                                        SQUASHFS_METADATA_SIZE)

#define SQUASHFS_ID_BLOCK_OFFSET(A)     (SQUASHFS_ID_BYTES(A) % \
                                        SQUASHFS_METADATA_SIZE)

#define SQUASHFS_ID_BLOCKS(A)           ((SQUASHFS_ID_BYTES(A) + \
                                        SQUASHFS_METADATA_SIZE - 1) / \
                                        SQUASHFS_METADATA_SIZE)

#define SQUASHFS_ID_BLOCK_BYTES(A)      (SQUASHFS_ID_BLOCKS(A) *\
                                        sizeof(u64))
/* xattr id lookup table defines */
#define SQUASHFS_XATTR_BYTES(A)         (((u64) (A)) * sizeof(struct squashfs_xattr_id))

#define SQUASHFS_XATTR_BLOCK(A)         (SQUASHFS_XATTR_BYTES(A) / \
                                        SQUASHFS_METADATA_SIZE)

#define SQUASHFS_XATTR_BLOCK_OFFSET(A)  (SQUASHFS_XATTR_BYTES(A) % \
                                        SQUASHFS_METADATA_SIZE)

#define SQUASHFS_XATTR_BLOCKS(A)        ((SQUASHFS_XATTR_BYTES(A) + \
                                        SQUASHFS_METADATA_SIZE - 1) / \
                                        SQUASHFS_METADATA_SIZE)

#define SQUASHFS_XATTR_BLOCK_BYTES(A)   (SQUASHFS_XATTR_BLOCKS(A) *\
                                        sizeof(u64))
#define SQUASHFS_XATTR_BLK(A)           ((unsigned int) ((A) >> 16))

#define SQUASHFS_XATTR_OFFSET(A)        ((unsigned int) ((A) & 0xffff))

/* cached data constants for filesystem */
#define SQUASHFS_CACHED_BLKS            8

/* meta index cache */
#define SQUASHFS_META_INDEXES   (SQUASHFS_METADATA_SIZE / sizeof(unsigned int))
#define SQUASHFS_META_ENTRIES   127
#define SQUASHFS_META_SLOTS     8
#define SQUASHFS_SCAN_INDEXES   1024

struct meta_entry {
        u64                     data_block;
        unsigned int            index_block;
        unsigned short          offset;
        unsigned short          pad;
};

struct meta_index {
        unsigned int            inode_number;
        unsigned int            offset;
        unsigned short          entries;
        unsigned short          skip;
        unsigned short          locked;
        unsigned short          pad;
        struct meta_entry       meta_entry[SQUASHFS_META_ENTRIES];
};


/*
 * definitions for structures on disk
 */
#define ZLIB_COMPRESSION        1
#define LZMA_COMPRESSION        2
#define LZO_COMPRESSION         3
#define XZ_COMPRESSION          4
#define LZ4_COMPRESSION         5
#define ZSTD_COMPRESSION        6

struct squashfs_super_block {
        __le32                  s_magic;
        __le32                  inodes;
        __le32                  mkfs_time;
        __le32                  block_size;
        __le32                  fragments;
        __le16                  compression;
        __le16                  block_log;
        __le16                  flags;
        __le16                  no_ids;
        __le16                  s_major;
        __le16                  s_minor;
        __le64                  root_inode;
        __le64                  bytes_used;
        __le64                  id_table_start;
        __le64                  xattr_id_table_start;
        __le64                  inode_table_start;
        __le64                  directory_table_start;
        __le64                  fragment_table_start;
        __le64                  lookup_table_start;
};

struct squashfs_dir_index {
        __le32                  index;
        __le32                  start_block;
        __le32                  size;
        unsigned char           name[];
};

struct squashfs_base_inode {
        __le16                  inode_type;
        __le16                  mode;
        __le16                  uid;
        __le16                  guid;
        __le32                  mtime;
        __le32                  inode_number;
};

struct squashfs_ipc_inode {
        __le16                  inode_type;
        __le16                  mode;
        __le16                  uid;
        __le16                  guid;
        __le32                  mtime;
        __le32                  inode_number;
        __le32                  nlink;
};

struct squashfs_lipc_inode {
        __le16                  inode_type;
        __le16                  mode;
        __le16                  uid;
        __le16                  guid;
        __le32                  mtime;
        __le32                  inode_number;
        __le32                  nlink;
        __le32                  xattr;
};

struct squashfs_dev_inode {
        __le16                  inode_type;
        __le16                  mode;
        __le16                  uid;
        __le16                  guid;
        __le32                  mtime;
        __le32                  inode_number;
        __le32                  nlink;
        __le32                  rdev;
};

struct squashfs_ldev_inode {
        __le16                  inode_type;
        __le16                  mode;
        __le16                  uid;
        __le16                  guid;
        __le32                  mtime;
        __le32                  inode_number;
        __le32                  nlink;
        __le32                  rdev;
        __le32                  xattr;
};

struct squashfs_symlink_inode {
        __le16                  inode_type;
        __le16                  mode;
        __le16                  uid;
        __le16                  guid;
        __le32                  mtime;
        __le32                  inode_number;
        __le32                  nlink;
        __le32                  symlink_size;
        char                    symlink[];
};

struct squashfs_reg_inode {
        __le16                  inode_type;
        __le16                  mode;
        __le16                  uid;
        __le16                  guid;
        __le32                  mtime;
        __le32                  inode_number;
        __le32                  start_block;
        __le32                  fragment;
        __le32                  offset;
        __le32                  file_size;
        __le16                  block_list[];
};

struct squashfs_lreg_inode {
        __le16                  inode_type;
        __le16                  mode;
        __le16                  uid;
        __le16                  guid;
        __le32                  mtime;
        __le32                  inode_number;
        __le64                  start_block;
        __le64                  file_size;
        __le64                  sparse;
        __le32                  nlink;
        __le32                  fragment;
        __le32                  offset;
        __le32                  xattr;
        __le16                  block_list[];
};

struct squashfs_dir_inode {
        __le16                  inode_type;
        __le16                  mode;
        __le16                  uid;
        __le16                  guid;
        __le32                  mtime;
        __le32                  inode_number;
        __le32                  start_block;
        __le32                  nlink;
        __le16                  file_size;
        __le16                  offset;
        __le32                  parent_inode;
};

struct squashfs_ldir_inode {
        __le16                  inode_type;
        __le16                  mode;
        __le16                  uid;
        __le16                  guid;
        __le32                  mtime;
        __le32                  inode_number;
        __le32                  nlink;
        __le32                  file_size;
        __le32                  start_block;
        __le32                  parent_inode;
        __le16                  i_count;
        __le16                  offset;
        __le32                  xattr;
        struct squashfs_dir_index       index[];
};

union squashfs_inode {
        struct squashfs_base_inode              base;
        struct squashfs_dev_inode               dev;
        struct squashfs_ldev_inode              ldev;
        struct squashfs_symlink_inode           symlink;
        struct squashfs_reg_inode               reg;
        struct squashfs_lreg_inode              lreg;
        struct squashfs_dir_inode               dir;
        struct squashfs_ldir_inode              ldir;
        struct squashfs_ipc_inode               ipc;
        struct squashfs_lipc_inode              lipc;
};

struct squashfs_dir_entry {
        __le16                  offset;
        __le16                  inode_number;
        __le16                  type;
        __le16                  size;
        char                    name[];
};

struct squashfs_dir_header {
        __le32                  count;
        __le32                  start_block;
        __le32                  inode_number;
};

struct squashfs_fragment_entry {
        __le64                  start_block;
        __le32                  size;
        unsigned int            unused;
};

struct squashfs_xattr_entry {
        __le16                  type;
        __le16                  size;
        char                    data[];
};

struct squashfs_xattr_val {
        __le32                  vsize;
        char                    value[];
};

struct squashfs_xattr_id {
        __le64                  xattr;
        __le32                  count;
        __le32                  size;
};

struct squashfs_xattr_id_table {
        __le64                  xattr_table_start;
        __le32                  xattr_ids;
        __le32                  unused;
};

#endif