LXR uboot/fs/squashfs/sqfs

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2020 Bootlin
   4 *
   5 * Author: Joao Marcos Costa <joaomarcos.costa@bootlin.com>
   6 */
   7
   8#include <errno.h>
   9#include <linux/types.h>
  10#include <linux/byteorder/little_endian.h>
  11#include <linux/byteorder/generic.h>
  12#include <stdint.h>
  13#include <stdio.h>
  14#include <stdlib.h>
  15
  16#include "sqfs_filesystem.h"
  17#include "sqfs_utils.h"
  18
  19bool sqfs_is_dir(u16 type)
  20{
  21        return type == SQFS_DIR_TYPE || type == SQFS_LDIR_TYPE;
  22}
  23
  24/*
  25 * Receives a pointer (void *) to a position in the inode table containing the
  26 * directory's inode. Returns directory inode offset into the directory table.
  27 * m_list contains each metadata block's position, and m_count is the number of
  28 * elements of m_list. Those metadata blocks come from the compressed directory
  29 * table.
  30 */
  31int sqfs_dir_offset(void *dir_i, u32 *m_list, int m_count)
  32{
  33        struct squashfs_base_inode *base = dir_i;
  34        struct squashfs_ldir_inode *ldir;
  35        struct squashfs_dir_inode *dir;
  36        u32 start_block;
  37        int j, offset;
  38
  39        switch (get_unaligned_le16(&base->inode_type)) {
  40        case SQFS_DIR_TYPE:
  41                dir = (struct squashfs_dir_inode *)base;
  42                start_block = get_unaligned_le32(&dir->start_block);
  43                offset = get_unaligned_le16(&dir->offset);
  44                break;
  45        case SQFS_LDIR_TYPE:
  46                ldir = (struct squashfs_ldir_inode *)base;
  47                start_block = get_unaligned_le32(&ldir->start_block);
  48                offset = get_unaligned_le16(&ldir->offset);
  49                break;
  50        default:
  51                printf("Error: this is not a directory.\n");
  52                return -EINVAL;
  53        }
  54
  55        if (offset < 0)
  56                return -EINVAL;
  57
  58        for (j = 0; j < m_count; j++) {
  59                if (m_list[j] == start_block)
  60                        return (++j * SQFS_METADATA_BLOCK_SIZE) + offset;
  61        }
  62
  63        if (start_block == 0)
  64                return offset;
  65
  66        printf("Error: invalid inode reference to directory table.\n");
  67
  68        return -EINVAL;
  69}
  70
  71bool sqfs_is_empty_dir(void *dir_i)
  72{
  73        struct squashfs_base_inode *base = dir_i;
  74        struct squashfs_ldir_inode *ldir;
  75        struct squashfs_dir_inode *dir;
  76        u32 file_size;
  77
  78        switch (get_unaligned_le16(&base->inode_type)) {
  79        case SQFS_DIR_TYPE:
  80                dir = (struct squashfs_dir_inode *)base;
  81                file_size = get_unaligned_le16(&dir->file_size);
  82                break;
  83        case SQFS_LDIR_TYPE:
  84                ldir = (struct squashfs_ldir_inode *)base;
  85                file_size = get_unaligned_le16(&ldir->file_size);
  86                break;
  87        default:
  88                printf("Error: this is not a directory.\n");
  89                return false;
  90        }
  91
  92        return file_size == SQFS_EMPTY_FILE_SIZE;
  93}
  94