94 lines
2.3 KiB
C
94 lines
2.3 KiB
C
// 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;
|
|
}
|