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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;
int j, offset;
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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