105 lines
2.5 KiB
C
105 lines
2.5 KiB
C
/*
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* check_desc.c --- Check the group descriptors of an ext2 filesystem
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*
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* Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
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*
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* %Begin-Header%
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* This file may be redistributed under the terms of the GNU Library
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* General Public License, version 2.
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* %End-Header%
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*/
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#include "config.h"
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#include <stdio.h>
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#include <string.h>
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#if HAVE_UNISTD_H
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#include <unistd.h>
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#endif
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#include <fcntl.h>
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#include <time.h>
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#if HAVE_SYS_STAT_H
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#include <sys/stat.h>
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#endif
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#if HAVE_SYS_TYPES_H
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#include <sys/types.h>
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#endif
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#include "ext2_fs.h"
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#include "ext2fs.h"
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/*
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* This routine sanity checks the group descriptors
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*/
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errcode_t ext2fs_check_desc(ext2_filsys fs)
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{
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ext2fs_block_bitmap bmap;
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errcode_t retval;
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dgrp_t i;
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blk64_t first_block = fs->super->s_first_data_block;
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blk64_t last_block = ext2fs_blocks_count(fs->super)-1;
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blk64_t blk, b;
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unsigned int j;
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EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
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if (EXT2_DESC_SIZE(fs->super) & (EXT2_DESC_SIZE(fs->super) - 1))
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return EXT2_ET_BAD_DESC_SIZE;
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retval = ext2fs_allocate_subcluster_bitmap(fs, "check_desc map", &bmap);
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if (retval)
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return retval;
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for (i = 0; i < fs->group_desc_count; i++)
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ext2fs_reserve_super_and_bgd(fs, i, bmap);
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for (i = 0; i < fs->group_desc_count; i++) {
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if (!ext2fs_has_feature_flex_bg(fs->super)) {
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first_block = ext2fs_group_first_block2(fs, i);
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last_block = ext2fs_group_last_block2(fs, i);
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}
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/*
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* Check to make sure the block bitmap for group is sane
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*/
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blk = ext2fs_block_bitmap_loc(fs, i);
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if (blk < first_block || blk > last_block ||
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ext2fs_test_block_bitmap2(bmap, blk)) {
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retval = EXT2_ET_GDESC_BAD_BLOCK_MAP;
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goto errout;
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}
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ext2fs_mark_block_bitmap2(bmap, blk);
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/*
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* Check to make sure the inode bitmap for group is sane
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*/
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blk = ext2fs_inode_bitmap_loc(fs, i);
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if (blk < first_block || blk > last_block ||
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ext2fs_test_block_bitmap2(bmap, blk)) {
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retval = EXT2_ET_GDESC_BAD_INODE_MAP;
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goto errout;
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}
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ext2fs_mark_block_bitmap2(bmap, blk);
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/*
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* Check to make sure the inode table for group is sane
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*/
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blk = ext2fs_inode_table_loc(fs, i);
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if (blk < first_block ||
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((blk + fs->inode_blocks_per_group - 1) > last_block)) {
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retval = EXT2_ET_GDESC_BAD_INODE_TABLE;
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goto errout;
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}
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for (j = 0, b = blk; j < fs->inode_blocks_per_group;
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j++, b++) {
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if (ext2fs_test_block_bitmap2(bmap, b)) {
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retval = EXT2_ET_GDESC_BAD_INODE_TABLE;
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goto errout;
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}
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ext2fs_mark_block_bitmap2(bmap, b);
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}
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}
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errout:
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ext2fs_free_block_bitmap(bmap);
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return retval;
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}
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