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