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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Copyright (C) 2020 Bootlin
- *
- * Author: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
- */
- #include <errno.h>
- #include <linux/types.h>
- #include <linux/byteorder/little_endian.h>
- #include <linux/byteorder/generic.h>
- #include <stdint.h>
- #include <stdio.h>
- #include <stdlib.h>
- #include "sqfs_filesystem.h"
- #include "sqfs_utils.h"
- bool sqfs_is_dir(u16 type)
- {
- return type == SQFS_DIR_TYPE || type == SQFS_LDIR_TYPE;
- }
- /*
- * Receives a pointer (void *) to a position in the inode table containing the
- * directory's inode. Returns directory inode offset into the directory table.
- * m_list contains each metadata block's position, and m_count is the number of
- * elements of m_list. Those metadata blocks come from the compressed directory
- * table.
- */
- int sqfs_dir_offset(void *dir_i, u32 *m_list, int m_count)
- {
- struct squashfs_base_inode *base = dir_i;
- struct squashfs_ldir_inode *ldir;
- struct squashfs_dir_inode *dir;
- u32 start_block;
- u16 offset;
- int j;
- switch (get_unaligned_le16(&base->inode_type)) {
- case SQFS_DIR_TYPE:
- dir = (struct squashfs_dir_inode *)base;
- start_block = get_unaligned_le32(&dir->start_block);
- offset = get_unaligned_le16(&dir->offset);
- break;
- case SQFS_LDIR_TYPE:
- ldir = (struct squashfs_ldir_inode *)base;
- start_block = get_unaligned_le32(&ldir->start_block);
- offset = get_unaligned_le16(&ldir->offset);
- break;
- default:
- printf("Error: this is not a directory.\n");
- return -EINVAL;
- }
- if (offset < 0)
- return -EINVAL;
- for (j = 0; j < m_count; j++) {
- if (m_list[j] == start_block)
- return (++j * SQFS_METADATA_BLOCK_SIZE) + offset;
- }
- if (start_block == 0)
- return offset;
- printf("Error: invalid inode reference to directory table.\n");
- return -EINVAL;
- }
- bool sqfs_is_empty_dir(void *dir_i)
- {
- struct squashfs_base_inode *base = dir_i;
- struct squashfs_ldir_inode *ldir;
- struct squashfs_dir_inode *dir;
- u32 file_size;
- switch (get_unaligned_le16(&base->inode_type)) {
- case SQFS_DIR_TYPE:
- dir = (struct squashfs_dir_inode *)base;
- file_size = get_unaligned_le16(&dir->file_size);
- break;
- case SQFS_LDIR_TYPE:
- ldir = (struct squashfs_ldir_inode *)base;
- file_size = get_unaligned_le16(&ldir->file_size);
- break;
- default:
- printf("Error: this is not a directory.\n");
- return false;
- }
- return file_size == SQFS_EMPTY_FILE_SIZE;
- }
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