Break up squashfs.h into topic related headers

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

13 files changed, 345 insertions, 282 deletions

diff --git a/include/data_reader.h b/include/data_reader.h
index 4a4763e..feba7a1 100644
--- a/include/data_reader.h
+++ b/include/data_reader.h
@@ -9,8 +9,8 @@
 
 #include "config.h"
 
-#include "sqfs/squashfs.h"
 #include "sqfs/compress.h"
+#include "sqfs/data.h"
 #include "fstree.h"
 
 typedef struct data_reader_t data_reader_t;
diff --git a/include/data_writer.h b/include/data_writer.h
index 7b1142f..081c468 100644
--- a/include/data_writer.h
+++ b/include/data_writer.h
@@ -9,8 +9,8 @@
 
 #include "config.h"
 
-#include "sqfs/squashfs.h"
 #include "sqfs/compress.h"
+#include "sqfs/data.h"
 #include "fstree.h"
 #include "util.h"
 
diff --git a/include/highlevel.h b/include/highlevel.h
index aae02cf..bea674e 100644
--- a/include/highlevel.h
+++ b/include/highlevel.h
@@ -9,9 +9,10 @@
 
 #include "config.h"
 
-#include "sqfs/squashfs.h"
 #include "sqfs/compress.h"
 #include "sqfs/id_table.h"
+#include "sqfs/inode.h"
+#include "sqfs/data.h"
 #include "data_reader.h"
 #include "fstree.h"
 
diff --git a/include/sqfs/compress.h b/include/sqfs/compress.h
index 1dfba12..c6de185 100644
--- a/include/sqfs/compress.h
+++ b/include/sqfs/compress.h
@@ -14,7 +14,7 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#include "squashfs.h"
+#include "sqfs/super.h"
 
 typedef struct compressor_t compressor_t;
 
diff --git a/include/sqfs/data.h b/include/sqfs/data.h
new file mode 100644
index 0000000..1b70f45
--- /dev/null
+++ b/include/sqfs/data.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * data.h
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#ifndef SQFS_DATA_H
+#define SQFS_DATA_H
+
+#include "config.h"
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stddef.h>
+
+#define SQFS_META_BLOCK_SIZE 8192
+
+#define SQFS_IS_BLOCK_COMPRESSED(size) (((size) & (1 << 24)) == 0)
+#define SQFS_ON_DISK_BLOCK_SIZE(size) ((size) & ((1 << 24) - 1))
+#define SQFS_IS_SPARSE_BLOCK(size) (SQFS_ON_DISK_BLOCK_SIZE(size) == 0)
+
+typedef struct {
+	uint64_t start_offset;
+	uint32_t size;
+	uint32_t pad0;
+} sqfs_fragment_t;
+
+#endif /* SQFS_DATA_H */
diff --git a/include/sqfs/dir.h b/include/sqfs/dir.h
new file mode 100644
index 0000000..a1ca69c
--- /dev/null
+++ b/include/sqfs/dir.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * dir.h
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#ifndef SQFS_DIR_H
+#define SQFS_DIR_H
+
+#include "config.h"
+
+#include <stdint.h>
+
+#define SQFS_MAX_DIR_ENT 256
+
+typedef struct {
+	uint32_t count;
+	uint32_t start_block;
+	uint32_t inode_number;
+} sqfs_dir_header_t;
+
+typedef struct {
+	uint16_t offset;
+	int16_t inode_diff;
+	uint16_t type;
+	uint16_t size;
+	uint8_t name[];
+} sqfs_dir_entry_t;
+
+typedef struct {
+	uint32_t index;
+	uint32_t start_block;
+	uint32_t size;
+	uint8_t name[];
+} sqfs_dir_index_t;
+
+#endif /* SQFS_DIR_H */
diff --git a/include/sqfs/inode.h b/include/sqfs/inode.h
new file mode 100644
index 0000000..ac809d3
--- /dev/null
+++ b/include/sqfs/inode.h
@@ -0,0 +1,131 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * inode.h
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#ifndef SQFS_INODE_H
+#define SQFS_INODE_H
+
+#include "config.h"
+
+#include <stdint.h>
+
+typedef enum {
+	SQFS_INODE_DIR = 1,
+	SQFS_INODE_FILE = 2,
+	SQFS_INODE_SLINK = 3,
+	SQFS_INODE_BDEV = 4,
+	SQFS_INODE_CDEV = 5,
+	SQFS_INODE_FIFO = 6,
+	SQFS_INODE_SOCKET = 7,
+	SQFS_INODE_EXT_DIR = 8,
+	SQFS_INODE_EXT_FILE = 9,
+	SQFS_INODE_EXT_SLINK = 10,
+	SQFS_INODE_EXT_BDEV = 11,
+	SQFS_INODE_EXT_CDEV = 12,
+	SQFS_INODE_EXT_FIFO = 13,
+	SQFS_INODE_EXT_SOCKET = 14,
+} E_SQFS_INODE_TYPE;
+
+typedef struct {
+	uint16_t type;
+	uint16_t mode;
+	uint16_t uid_idx;
+	uint16_t gid_idx;
+	uint32_t mod_time;
+	uint32_t inode_number;
+} sqfs_inode_t;
+
+typedef struct {
+	uint32_t nlink;
+	uint32_t devno;
+} sqfs_inode_dev_t;
+
+typedef struct {
+	uint32_t nlink;
+	uint32_t devno;
+	uint32_t xattr_idx;
+} sqfs_inode_dev_ext_t;
+
+typedef struct {
+	uint32_t nlink;
+} sqfs_inode_ipc_t;
+
+typedef struct {
+	uint32_t nlink;
+	uint32_t xattr_idx;
+} sqfs_inode_ipc_ext_t;
+
+typedef struct {
+	uint32_t nlink;
+	uint32_t target_size;
+	/*uint8_t target[];*/
+} sqfs_inode_slink_t;
+
+typedef struct {
+	uint32_t nlink;
+	uint32_t target_size;
+	/*uint8_t target[];*/
+	uint32_t xattr_idx;
+} sqfs_inode_slink_ext_t;
+
+typedef struct {
+	uint32_t blocks_start;
+	uint32_t fragment_index;
+	uint32_t fragment_offset;
+	uint32_t file_size;
+	/*uint32_t block_sizes[];*/
+} sqfs_inode_file_t;
+
+typedef struct {
+	uint64_t blocks_start;
+	uint64_t file_size;
+	uint64_t sparse;
+	uint32_t nlink;
+	uint32_t fragment_idx;
+	uint32_t fragment_offset;
+	uint32_t xattr_idx;
+	/*uint32_t block_sizes[];*/
+} sqfs_inode_file_ext_t;
+
+typedef struct {
+	uint32_t start_block;
+	uint32_t nlink;
+	uint16_t size;
+	uint16_t offset;
+	uint32_t parent_inode;
+} sqfs_inode_dir_t;
+
+typedef struct {
+	uint32_t nlink;
+	uint32_t size;
+	uint32_t start_block;
+	uint32_t parent_inode;
+	uint16_t inodex_count;
+	uint16_t offset;
+	uint32_t xattr_idx;
+} sqfs_inode_dir_ext_t;
+
+typedef struct {
+	sqfs_inode_t base;
+	char *slink_target;
+	uint32_t *block_sizes;
+
+	union {
+		sqfs_inode_dev_t dev;
+		sqfs_inode_dev_ext_t dev_ext;
+		sqfs_inode_ipc_t ipc;
+		sqfs_inode_ipc_ext_t ipc_ext;
+		sqfs_inode_slink_t slink;
+		sqfs_inode_slink_ext_t slink_ext;
+		sqfs_inode_file_t file;
+		sqfs_inode_file_ext_t file_ext;
+		sqfs_inode_dir_t dir;
+		sqfs_inode_dir_ext_t dir_ext;
+	} data;
+
+	uint8_t extra[];
+} sqfs_inode_generic_t;
+
+#endif /* SQFS_INODE_H */
diff --git a/include/sqfs/meta_reader.h b/include/sqfs/meta_reader.h
index d5628af..0de7401 100644
--- a/include/sqfs/meta_reader.h
+++ b/include/sqfs/meta_reader.h
@@ -9,8 +9,10 @@
 
 #include "config.h"
 
-#include "compress.h"
-#include "squashfs.h"
+#include "sqfs/compress.h"
+#include "sqfs/inode.h"
+#include "sqfs/data.h"
+#include "sqfs/dir.h"
 
 typedef struct meta_reader_t meta_reader_t;
 
diff --git a/include/sqfs/meta_writer.h b/include/sqfs/meta_writer.h
index 762cc38..6c56c93 100644
--- a/include/sqfs/meta_writer.h
+++ b/include/sqfs/meta_writer.h
@@ -9,9 +9,9 @@
 
 #include "config.h"
 
-#include "compress.h"
-#include "squashfs.h"
-#include "id_table.h"
+#include "sqfs/compress.h"
+#include "sqfs/id_table.h"
+#include "sqfs/data.h"
 #include "fstree.h"
 
 typedef struct {
diff --git a/include/sqfs/squashfs.h b/include/sqfs/squashfs.h
deleted file mode 100644
index eb35fdd..0000000
--- a/include/sqfs/squashfs.h
+++ /dev/null
@@ -1,272 +0,0 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
-/*
- * squashfs.h
- *
- * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
- */
-#ifndef SQUASHFS_H
-#define SQUASHFS_H
-
-#include "config.h"
-
-#include <stdbool.h>
-#include <stdint.h>
-#include <stddef.h>
-
-#define SQFS_MAGIC 0x73717368
-#define SQFS_VERSION_MAJOR 4
-#define SQFS_VERSION_MINOR 0
-#define SQFS_META_BLOCK_SIZE 8192
-#define SQFS_DEFAULT_BLOCK_SIZE 131072
-#define SQFS_DEVBLK_SIZE 4096
-#define SQFS_MAX_DIR_ENT 256
-
-#define SQFS_IS_BLOCK_COMPRESSED(size) (((size) & (1 << 24)) == 0)
-#define SQFS_ON_DISK_BLOCK_SIZE(size) ((size) & ((1 << 24) - 1))
-#define SQFS_IS_SPARSE_BLOCK(size) (SQFS_ON_DISK_BLOCK_SIZE(size) == 0)
-
-typedef struct {
-	uint32_t magic;
-	uint32_t inode_count;
-	uint32_t modification_time;
-	uint32_t block_size;
-	uint32_t fragment_entry_count;
-	uint16_t compression_id;
-	uint16_t block_log;
-	uint16_t flags;
-	uint16_t id_count;
-	uint16_t version_major;
-	uint16_t version_minor;
-	uint64_t root_inode_ref;
-	uint64_t bytes_used;
-	uint64_t id_table_start;
-	uint64_t xattr_id_table_start;
-	uint64_t inode_table_start;
-	uint64_t directory_table_start;
-	uint64_t fragment_table_start;
-	uint64_t export_table_start;
-} __attribute__((packed)) sqfs_super_t;
-
-typedef struct {
-	uint64_t start_offset;
-	uint32_t size;
-	uint32_t pad0;
-} sqfs_fragment_t;
-
-typedef struct {
-	uint16_t type;
-	uint16_t mode;
-	uint16_t uid_idx;
-	uint16_t gid_idx;
-	uint32_t mod_time;
-	uint32_t inode_number;
-} sqfs_inode_t;
-
-typedef struct {
-	uint32_t nlink;
-	uint32_t devno;
-} sqfs_inode_dev_t;
-
-typedef struct {
-	uint32_t nlink;
-	uint32_t devno;
-	uint32_t xattr_idx;
-} sqfs_inode_dev_ext_t;
-
-typedef struct {
-	uint32_t nlink;
-} sqfs_inode_ipc_t;
-
-typedef struct {
-	uint32_t nlink;
-	uint32_t xattr_idx;
-} sqfs_inode_ipc_ext_t;
-
-typedef struct {
-	uint32_t nlink;
-	uint32_t target_size;
-	/*uint8_t target[];*/
-} sqfs_inode_slink_t;
-
-typedef struct {
-	uint32_t nlink;
-	uint32_t target_size;
-	/*uint8_t target[];*/
-	uint32_t xattr_idx;
-} sqfs_inode_slink_ext_t;
-
-typedef struct {
-	uint32_t blocks_start;
-	uint32_t fragment_index;
-	uint32_t fragment_offset;
-	uint32_t file_size;
-	/*uint32_t block_sizes[];*/
-} sqfs_inode_file_t;
-
-typedef struct {
-	uint64_t blocks_start;
-	uint64_t file_size;
-	uint64_t sparse;
-	uint32_t nlink;
-	uint32_t fragment_idx;
-	uint32_t fragment_offset;
-	uint32_t xattr_idx;
-	/*uint32_t block_sizes[];*/
-} sqfs_inode_file_ext_t;
-
-typedef struct {
-	uint32_t start_block;
-	uint32_t nlink;
-	uint16_t size;
-	uint16_t offset;
-	uint32_t parent_inode;
-} sqfs_inode_dir_t;
-
-typedef struct {
-	uint32_t nlink;
-	uint32_t size;
-	uint32_t start_block;
-	uint32_t parent_inode;
-	uint16_t inodex_count;
-	uint16_t offset;
-	uint32_t xattr_idx;
-} sqfs_inode_dir_ext_t;
-
-typedef struct {
-	sqfs_inode_t base;
-	char *slink_target;
-	uint32_t *block_sizes;
-
-	union {
-		sqfs_inode_dev_t dev;
-		sqfs_inode_dev_ext_t dev_ext;
-		sqfs_inode_ipc_t ipc;
-		sqfs_inode_ipc_ext_t ipc_ext;
-		sqfs_inode_slink_t slink;
-		sqfs_inode_slink_ext_t slink_ext;
-		sqfs_inode_file_t file;
-		sqfs_inode_file_ext_t file_ext;
-		sqfs_inode_dir_t dir;
-		sqfs_inode_dir_ext_t dir_ext;
-	} data;
-
-	uint8_t extra[];
-} sqfs_inode_generic_t;
-
-typedef struct {
-	uint32_t count;
-	uint32_t start_block;
-	uint32_t inode_number;
-} sqfs_dir_header_t;
-
-typedef struct {
-	uint16_t offset;
-	int16_t inode_diff;
-	uint16_t type;
-	uint16_t size;
-	uint8_t name[];
-} sqfs_dir_entry_t;
-
-typedef struct {
-	uint32_t index;
-	uint32_t start_block;
-	uint32_t size;
-	uint8_t name[];
-} sqfs_dir_index_t;
-
-typedef struct {
-	uint16_t type;
-	uint16_t size;
-	uint8_t key[];
-} sqfs_xattr_entry_t;
-
-typedef struct {
-	uint32_t size;
-	uint8_t value[];
-} sqfs_xattr_value_t;
-
-typedef struct {
-	uint64_t xattr;
-	uint32_t count;
-	uint32_t size;
-} sqfs_xattr_id_t;
-
-typedef struct {
-	uint64_t xattr_table_start;
-	uint32_t xattr_ids;
-	uint32_t unused;
-} sqfs_xattr_id_table_t;
-
-
-typedef enum {
-	SQFS_COMP_GZIP = 1,
-	SQFS_COMP_LZMA = 2,
-	SQFS_COMP_LZO = 3,
-	SQFS_COMP_XZ = 4,
-	SQFS_COMP_LZ4 = 5,
-	SQFS_COMP_ZSTD = 6,
-
-	SQFS_COMP_MIN = 1,
-	SQFS_COMP_MAX = 6,
-} E_SQFS_COMPRESSOR;
-
-typedef enum {
-	SQFS_FLAG_UNCOMPRESSED_INODES = 0x0001,
-	SQFS_FLAG_UNCOMPRESSED_DATA = 0x0002,
-	SQFS_FLAG_UNCOMPRESSED_FRAGMENTS = 0x0008,
-	SQFS_FLAG_NO_FRAGMENTS = 0x0010,
-	SQFS_FLAG_ALWAYS_FRAGMENTS = 0x0020,
-	SQFS_FLAG_DUPLICATES = 0x0040,
-	SQFS_FLAG_EXPORTABLE = 0x0080,
-	SQFS_FLAG_UNCOMPRESSED_XATTRS = 0x0100,
-	SQFS_FLAG_NO_XATTRS = 0x0200,
-	SQFS_FLAG_COMPRESSOR_OPTIONS = 0x0400,
-	SQFS_FLAG_UNCOMPRESSED_IDS = 0x0800,
-} E_SQFS_SUPER_FLAGS;
-
-typedef enum {
-	SQFS_INODE_DIR = 1,
-	SQFS_INODE_FILE = 2,
-	SQFS_INODE_SLINK = 3,
-	SQFS_INODE_BDEV = 4,
-	SQFS_INODE_CDEV = 5,
-	SQFS_INODE_FIFO = 6,
-	SQFS_INODE_SOCKET = 7,
-	SQFS_INODE_EXT_DIR = 8,
-	SQFS_INODE_EXT_FILE = 9,
-	SQFS_INODE_EXT_SLINK = 10,
-	SQFS_INODE_EXT_BDEV = 11,
-	SQFS_INODE_EXT_CDEV = 12,
-	SQFS_INODE_EXT_FIFO = 13,
-	SQFS_INODE_EXT_SOCKET = 14,
-} E_SQFS_INODE_TYPE;
-
-typedef enum {
-	SQUASHFS_XATTR_USER = 0,
-	SQUASHFS_XATTR_TRUSTED = 1,
-	SQUASHFS_XATTR_SECURITY = 2,
-
-	SQUASHFS_XATTR_FLAG_OOL = 0x100,
-	SQUASHFS_XATTR_PREFIX_MASK = 0xFF,
-} E_SQFS_XATTR_TYPE;
-
-/* Returns 0 on success. Prints error messages to stderr on failure. */
-int sqfs_super_init(sqfs_super_t *super, size_t block_size, uint32_t mtime,
-		    E_SQFS_COMPRESSOR compressor);
-
-/* Returns 0 on success. Prints error messages to stderr on failure. */
-int sqfs_super_write(sqfs_super_t *super, int fd);
-
-/* Returns 0 on success. Prints error messages to stderr on failure. */
-int sqfs_super_read(sqfs_super_t *super, int fd);
-
-/* Get id from xattr key prefix or -1 if not supported */
-int sqfs_get_xattr_prefix_id(const char *key);
-
-/* Get a prefix string from the ID or NULL if unknown */
-const char *sqfs_get_xattr_prefix(E_SQFS_XATTR_TYPE id);
-
-/* Check if a given xattr key can be encoded in squashfs at all. */
-bool sqfs_has_xattr(const char *key);
-
-#endif /* SQUASHFS_H */
diff --git a/include/sqfs/super.h b/include/sqfs/super.h
new file mode 100644
index 0000000..51a3a9e
--- /dev/null
+++ b/include/sqfs/super.h
@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * super.h
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#ifndef SQFS_SUPER_H
+#define SQFS_SUPER_H
+
+#include "config.h"
+
+#include <stdint.h>
+#include <stddef.h>
+
+#define SQFS_MAGIC 0x73717368
+#define SQFS_VERSION_MAJOR 4
+#define SQFS_VERSION_MINOR 0
+#define SQFS_DEVBLK_SIZE 4096
+#define SQFS_DEFAULT_BLOCK_SIZE 131072
+
+typedef struct {
+	uint32_t magic;
+	uint32_t inode_count;
+	uint32_t modification_time;
+	uint32_t block_size;
+	uint32_t fragment_entry_count;
+	uint16_t compression_id;
+	uint16_t block_log;
+	uint16_t flags;
+	uint16_t id_count;
+	uint16_t version_major;
+	uint16_t version_minor;
+	uint64_t root_inode_ref;
+	uint64_t bytes_used;
+	uint64_t id_table_start;
+	uint64_t xattr_id_table_start;
+	uint64_t inode_table_start;
+	uint64_t directory_table_start;
+	uint64_t fragment_table_start;
+	uint64_t export_table_start;
+} __attribute__((packed)) sqfs_super_t;
+
+typedef enum {
+	SQFS_COMP_GZIP = 1,
+	SQFS_COMP_LZMA = 2,
+	SQFS_COMP_LZO = 3,
+	SQFS_COMP_XZ = 4,
+	SQFS_COMP_LZ4 = 5,
+	SQFS_COMP_ZSTD = 6,
+
+	SQFS_COMP_MIN = 1,
+	SQFS_COMP_MAX = 6,
+} E_SQFS_COMPRESSOR;
+
+typedef enum {
+	SQFS_FLAG_UNCOMPRESSED_INODES = 0x0001,
+	SQFS_FLAG_UNCOMPRESSED_DATA = 0x0002,
+	SQFS_FLAG_UNCOMPRESSED_FRAGMENTS = 0x0008,
+	SQFS_FLAG_NO_FRAGMENTS = 0x0010,
+	SQFS_FLAG_ALWAYS_FRAGMENTS = 0x0020,
+	SQFS_FLAG_DUPLICATES = 0x0040,
+	SQFS_FLAG_EXPORTABLE = 0x0080,
+	SQFS_FLAG_UNCOMPRESSED_XATTRS = 0x0100,
+	SQFS_FLAG_NO_XATTRS = 0x0200,
+	SQFS_FLAG_COMPRESSOR_OPTIONS = 0x0400,
+	SQFS_FLAG_UNCOMPRESSED_IDS = 0x0800,
+} E_SQFS_SUPER_FLAGS;
+
+/* Returns 0 on success. Prints error messages to stderr on failure. */
+int sqfs_super_init(sqfs_super_t *super, size_t block_size, uint32_t mtime,
+		    E_SQFS_COMPRESSOR compressor);
+
+/* Returns 0 on success. Prints error messages to stderr on failure. */
+int sqfs_super_write(sqfs_super_t *super, int fd);
+
+/* Returns 0 on success. Prints error messages to stderr on failure. */
+int sqfs_super_read(sqfs_super_t *super, int fd);
+
+#endif /* SQFS_SUPER_H */
diff --git a/include/sqfs/xattr.h b/include/sqfs/xattr.h
new file mode 100644
index 0000000..3d5da39
--- /dev/null
+++ b/include/sqfs/xattr.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * xattr.h
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#ifndef SQFS_XATTR_H
+#define SQFS_XATTR_H
+
+#include "config.h"
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <stddef.h>
+
+typedef enum {
+	SQUASHFS_XATTR_USER = 0,
+	SQUASHFS_XATTR_TRUSTED = 1,
+	SQUASHFS_XATTR_SECURITY = 2,
+
+	SQUASHFS_XATTR_FLAG_OOL = 0x100,
+	SQUASHFS_XATTR_PREFIX_MASK = 0xFF,
+} E_SQFS_XATTR_TYPE;
+
+typedef struct {
+	uint16_t type;
+	uint16_t size;
+	uint8_t key[];
+} sqfs_xattr_entry_t;
+
+typedef struct {
+	uint32_t size;
+	uint8_t value[];
+} sqfs_xattr_value_t;
+
+typedef struct {
+	uint64_t xattr;
+	uint32_t count;
+	uint32_t size;
+} sqfs_xattr_id_t;
+
+typedef struct {
+	uint64_t xattr_table_start;
+	uint32_t xattr_ids;
+	uint32_t unused;
+} sqfs_xattr_id_table_t;
+
+/* Get a prefix string from the ID or NULL if unknown */
+const char *sqfs_get_xattr_prefix(E_SQFS_XATTR_TYPE id);
+
+/* Get id from xattr key prefix or -1 if not supported */
+int sqfs_get_xattr_prefix_id(const char *key);
+
+/* Check if a given xattr key can be encoded in squashfs at all. */
+bool sqfs_has_xattr(const char *key);
+
+#endif /* SQFS_XATTR_H */
diff --git a/include/xattr_reader.h b/include/xattr_reader.h
index d9fe37b..9cacd35 100644
--- a/include/xattr_reader.h
+++ b/include/xattr_reader.h
@@ -9,8 +9,8 @@
 
 #include "config.h"
 
-#include "sqfs/squashfs.h"
 #include "sqfs/compress.h"
+#include "sqfs/data.h"
 #include "fstree.h"
 
 typedef struct xattr_reader_t xattr_reader_t;