1 files changed, 83 insertions, 0 deletions
diff --git a/lib/sqfs/src/read_super.c b/lib/sqfs/src/read_super.c
new file mode 100644
index 0000000..11bc314
--- /dev/null
+++ b/lib/sqfs/src/read_super.c
@@ -0,0 +1,83 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * read_super.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "config.h"
+
+#include "sqfs/super.h"
+#include "sqfs/error.h"
+#include "sqfs/io.h"
+#include "util/util.h"
+
+#include <string.h>
+
+int sqfs_super_read(sqfs_super_t *super, sqfs_file_t *file)
+{
+	size_t block_size = 0;
+	sqfs_super_t temp;
+	int i, ret;
+
+	ret = file->read_at(file, 0, &temp, sizeof(temp));
+	if (ret)
+		return ret;
+
+	temp.magic = le32toh(temp.magic);
+	temp.inode_count = le32toh(temp.inode_count);
+	temp.modification_time = le32toh(temp.modification_time);
+	temp.block_size = le32toh(temp.block_size);
+	temp.fragment_entry_count = le32toh(temp.fragment_entry_count);
+	temp.compression_id = le16toh(temp.compression_id);
+	temp.block_log = le16toh(temp.block_log);
+	temp.flags = le16toh(temp.flags);
+	temp.id_count = le16toh(temp.id_count);
+	temp.version_major = le16toh(temp.version_major);
+	temp.version_minor = le16toh(temp.version_minor);
+	temp.root_inode_ref = le64toh(temp.root_inode_ref);
+	temp.bytes_used = le64toh(temp.bytes_used);
+	temp.id_table_start = le64toh(temp.id_table_start);
+	temp.xattr_id_table_start = le64toh(temp.xattr_id_table_start);
+	temp.inode_table_start = le64toh(temp.inode_table_start);
+	temp.directory_table_start = le64toh(temp.directory_table_start);
+	temp.fragment_table_start = le64toh(temp.fragment_table_start);
+	temp.export_table_start = le64toh(temp.export_table_start);
+
+	if (temp.magic != SQFS_MAGIC)
+		return SFQS_ERROR_SUPER_MAGIC;
+
+	if ((temp.version_major != SQFS_VERSION_MAJOR) ||
+	    (temp.version_minor != SQFS_VERSION_MINOR))
+		return SFQS_ERROR_SUPER_VERSION;
+
+	if ((temp.block_size - 1) & temp.block_size)
+		return SQFS_ERROR_SUPER_BLOCK_SIZE;
+
+	if (temp.block_size < SQFS_MIN_BLOCK_SIZE)
+		return SQFS_ERROR_SUPER_BLOCK_SIZE;
+
+	if (temp.block_size > SQFS_MAX_BLOCK_SIZE)
+		return SQFS_ERROR_SUPER_BLOCK_SIZE;
+
+	if (temp.block_log < 12 || temp.block_log > 20)
+		return SQFS_ERROR_CORRUPTED;
+
+	block_size = 1;
+
+	for (i = 0; i < temp.block_log; ++i)
+		block_size <<= 1;
+
+	if (temp.block_size != block_size)
+		return SQFS_ERROR_CORRUPTED;
+
+	if (temp.compression_id < SQFS_COMP_MIN ||
+	    temp.compression_id > SQFS_COMP_MAX)
+		return SQFS_ERROR_UNSUPPORTED;
+
+	if (temp.id_count == 0)
+		return SQFS_ERROR_CORRUPTED;
+
+	memcpy(super, &temp, sizeof(temp));
+	return 0;
+}