1012 lines
27 KiB
C
1012 lines
27 KiB
C
/*
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* csum.c --- checksumming of ext3 structures
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*
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* Copyright (C) 2006 Cluster File Systems, Inc.
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* Copyright (C) 2006, 2007 by Andreas Dilger <adilger@clusterfs.com>
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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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#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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#include "crc16.h"
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#include <assert.h>
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#ifndef offsetof
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#define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
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#endif
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#ifdef DEBUG
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#define STATIC
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#else
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#define STATIC static
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#endif
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void ext2fs_init_csum_seed(ext2_filsys fs)
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{
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if (ext2fs_has_feature_csum_seed(fs->super))
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fs->csum_seed = fs->super->s_checksum_seed;
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else if (ext2fs_has_feature_metadata_csum(fs->super) ||
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ext2fs_has_feature_ea_inode(fs->super))
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fs->csum_seed = ext2fs_crc32c_le(~0, fs->super->s_uuid,
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sizeof(fs->super->s_uuid));
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}
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static __u32 ext2fs_mmp_csum(ext2_filsys fs, struct mmp_struct *mmp)
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{
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int offset = offsetof(struct mmp_struct, mmp_checksum);
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return ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)mmp, offset);
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}
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int ext2fs_mmp_csum_verify(ext2_filsys fs, struct mmp_struct *mmp)
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{
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__u32 calculated;
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if (!ext2fs_has_feature_metadata_csum(fs->super))
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return 1;
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calculated = ext2fs_mmp_csum(fs, mmp);
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return ext2fs_le32_to_cpu(mmp->mmp_checksum) == calculated;
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}
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errcode_t ext2fs_mmp_csum_set(ext2_filsys fs, struct mmp_struct *mmp)
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{
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__u32 crc;
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if (!ext2fs_has_feature_metadata_csum(fs->super))
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return 0;
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crc = ext2fs_mmp_csum(fs, mmp);
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mmp->mmp_checksum = ext2fs_cpu_to_le32(crc);
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return 0;
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}
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int ext2fs_verify_csum_type(ext2_filsys fs, struct ext2_super_block *sb)
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{
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if (!ext2fs_has_feature_metadata_csum(fs->super))
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return 1;
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return sb->s_checksum_type == EXT2_CRC32C_CHKSUM;
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}
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static __u32 ext2fs_superblock_csum(ext2_filsys fs EXT2FS_ATTR((unused)),
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struct ext2_super_block *sb)
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{
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int offset = offsetof(struct ext2_super_block, s_checksum);
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return ext2fs_crc32c_le(~0, (unsigned char *)sb, offset);
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}
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/* NOTE: The input to this function MUST be in LE order */
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int ext2fs_superblock_csum_verify(ext2_filsys fs, struct ext2_super_block *sb)
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{
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__u32 flag, calculated;
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if (fs->flags & EXT2_FLAG_SWAP_BYTES)
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flag = EXT4_FEATURE_RO_COMPAT_METADATA_CSUM;
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else
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flag = ext2fs_cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
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if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super, flag))
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return 1;
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calculated = ext2fs_superblock_csum(fs, sb);
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return ext2fs_le32_to_cpu(sb->s_checksum) == calculated;
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}
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/* NOTE: The input to this function MUST be in LE order */
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errcode_t ext2fs_superblock_csum_set(ext2_filsys fs,
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struct ext2_super_block *sb)
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{
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__u32 flag, crc;
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if (fs->flags & EXT2_FLAG_SWAP_BYTES)
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flag = EXT4_FEATURE_RO_COMPAT_METADATA_CSUM;
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else
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flag = ext2fs_cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
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if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super, flag))
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return 0;
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crc = ext2fs_superblock_csum(fs, sb);
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sb->s_checksum = ext2fs_cpu_to_le32(crc);
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return 0;
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}
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static errcode_t ext2fs_ext_attr_block_csum(ext2_filsys fs,
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ext2_ino_t inum EXT2FS_ATTR((unused)),
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blk64_t block,
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struct ext2_ext_attr_header *hdr,
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__u32 *crc)
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{
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char *buf = (char *)hdr;
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__u32 old_crc = hdr->h_checksum;
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hdr->h_checksum = 0;
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block = ext2fs_cpu_to_le64(block);
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*crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&block,
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sizeof(block));
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*crc = ext2fs_crc32c_le(*crc, (unsigned char *)buf, fs->blocksize);
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hdr->h_checksum = old_crc;
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return 0;
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}
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int ext2fs_ext_attr_block_csum_verify(ext2_filsys fs, ext2_ino_t inum,
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blk64_t block,
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struct ext2_ext_attr_header *hdr)
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{
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__u32 calculated;
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errcode_t retval;
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if (!ext2fs_has_feature_metadata_csum(fs->super))
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return 1;
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retval = ext2fs_ext_attr_block_csum(fs, inum, block, hdr, &calculated);
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if (retval)
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return 0;
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return ext2fs_le32_to_cpu(hdr->h_checksum) == calculated;
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}
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errcode_t ext2fs_ext_attr_block_csum_set(ext2_filsys fs, ext2_ino_t inum,
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blk64_t block,
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struct ext2_ext_attr_header *hdr)
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{
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errcode_t retval;
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__u32 crc;
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if (!ext2fs_has_feature_metadata_csum(fs->super))
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return 0;
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retval = ext2fs_ext_attr_block_csum(fs, inum, block, hdr, &crc);
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if (retval)
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return retval;
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hdr->h_checksum = ext2fs_cpu_to_le32(crc);
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return 0;
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}
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static __u16 do_nothing16(__u16 x)
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{
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return x;
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}
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static __u16 disk_to_host16(__u16 x)
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{
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return ext2fs_le16_to_cpu(x);
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}
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static errcode_t __get_dx_countlimit(ext2_filsys fs,
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struct ext2_dir_entry *dirent,
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struct ext2_dx_countlimit **cc,
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int *offset,
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int need_swab)
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{
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struct ext2_dir_entry *dp;
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struct ext2_dx_root_info *root;
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struct ext2_dx_countlimit *c;
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int count_offset, max_sane_entries;
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unsigned int rec_len;
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__u16 (*translate)(__u16) = (need_swab ? disk_to_host16 : do_nothing16);
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rec_len = translate(dirent->rec_len);
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if (rec_len == fs->blocksize && translate(dirent->name_len) == 0)
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count_offset = 8;
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else if (rec_len == 12) {
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dp = (struct ext2_dir_entry *)(((char *)dirent) + rec_len);
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rec_len = translate(dp->rec_len);
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if (rec_len != fs->blocksize - 12)
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return EXT2_ET_DB_NOT_FOUND;
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root = (struct ext2_dx_root_info *)(((char *)dp + 12));
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if (root->reserved_zero ||
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root->info_length != sizeof(struct ext2_dx_root_info))
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return EXT2_ET_DB_NOT_FOUND;
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count_offset = 32;
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} else
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return EXT2_ET_DB_NOT_FOUND;
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c = (struct ext2_dx_countlimit *)(((char *)dirent) + count_offset);
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max_sane_entries = (fs->blocksize - count_offset) /
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sizeof(struct ext2_dx_entry);
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if (ext2fs_le16_to_cpu(c->limit) > max_sane_entries ||
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ext2fs_le16_to_cpu(c->count) > max_sane_entries)
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return EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
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if (offset)
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*offset = count_offset;
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if (cc)
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*cc = c;
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return 0;
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}
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errcode_t ext2fs_get_dx_countlimit(ext2_filsys fs,
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struct ext2_dir_entry *dirent,
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struct ext2_dx_countlimit **cc,
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int *offset)
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{
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return __get_dx_countlimit(fs, dirent, cc, offset, 0);
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}
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void ext2fs_initialize_dirent_tail(ext2_filsys fs,
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struct ext2_dir_entry_tail *t)
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{
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memset(t, 0, sizeof(struct ext2_dir_entry_tail));
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ext2fs_set_rec_len(fs, sizeof(struct ext2_dir_entry_tail),
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(struct ext2_dir_entry *)t);
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t->det_reserved_name_len = EXT2_DIR_NAME_LEN_CSUM;
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}
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static errcode_t __get_dirent_tail(ext2_filsys fs,
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struct ext2_dir_entry *dirent,
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struct ext2_dir_entry_tail **tt,
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int need_swab)
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{
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struct ext2_dir_entry *d;
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void *top;
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struct ext2_dir_entry_tail *t;
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unsigned int rec_len;
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errcode_t retval = 0;
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__u16 (*translate)(__u16) = (need_swab ? disk_to_host16 : do_nothing16);
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if (fs->blocksize < 1024)
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return EXT2_FILSYS_CORRUPTED; /* Should never happen */
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d = dirent;
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top = EXT2_DIRENT_TAIL(dirent, fs->blocksize);
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while ((void *) d < top) {
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rec_len = translate(d->rec_len);
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if ((rec_len < 8) || (rec_len & 0x03))
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return EXT2_ET_DIR_CORRUPTED;
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d = (struct ext2_dir_entry *)(((char *)d) + rec_len);
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}
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if ((char *)d > ((char *)dirent + fs->blocksize))
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return EXT2_ET_DIR_CORRUPTED;
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if (d != top)
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return EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
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t = (struct ext2_dir_entry_tail *)d;
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if (t->det_reserved_zero1 ||
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translate(t->det_rec_len) != sizeof(struct ext2_dir_entry_tail) ||
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translate(t->det_reserved_name_len) != EXT2_DIR_NAME_LEN_CSUM)
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return EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
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if (tt)
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*tt = t;
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return retval;
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}
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int ext2fs_dirent_has_tail(ext2_filsys fs, struct ext2_dir_entry *dirent)
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{
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return __get_dirent_tail(fs, dirent, NULL, 0) !=
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EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
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}
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static errcode_t ext2fs_dirent_csum(ext2_filsys fs, ext2_ino_t inum,
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struct ext2_dir_entry *dirent, __u32 *crc,
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int size)
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{
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errcode_t retval;
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char *buf = (char *)dirent;
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__u32 gen;
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struct ext2_inode inode;
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retval = ext2fs_read_inode(fs, inum, &inode);
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if (retval)
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return retval;
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inum = ext2fs_cpu_to_le32(inum);
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gen = ext2fs_cpu_to_le32(inode.i_generation);
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*crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&inum,
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sizeof(inum));
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*crc = ext2fs_crc32c_le(*crc, (unsigned char *)&gen, sizeof(gen));
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*crc = ext2fs_crc32c_le(*crc, (unsigned char *)buf, size);
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return 0;
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}
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int ext2fs_dirent_csum_verify(ext2_filsys fs, ext2_ino_t inum,
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struct ext2_dir_entry *dirent)
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{
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errcode_t retval;
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__u32 calculated;
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struct ext2_dir_entry_tail *t;
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retval = __get_dirent_tail(fs, dirent, &t, 1);
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if (retval)
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return 1;
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/*
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* The checksum field is overlaid with the dirent->name field
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* so the swapfs.c functions won't change the endianness.
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*/
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retval = ext2fs_dirent_csum(fs, inum, dirent, &calculated,
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(char *)t - (char *)dirent);
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if (retval)
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return 0;
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return ext2fs_le32_to_cpu(t->det_checksum) == calculated;
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}
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static errcode_t ext2fs_dirent_csum_set(ext2_filsys fs, ext2_ino_t inum,
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struct ext2_dir_entry *dirent)
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{
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errcode_t retval;
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__u32 crc;
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struct ext2_dir_entry_tail *t;
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retval = __get_dirent_tail(fs, dirent, &t, 1);
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if (retval)
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return retval;
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/* swapfs.c functions don't change the checksum endianness */
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retval = ext2fs_dirent_csum(fs, inum, dirent, &crc,
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(char *)t - (char *)dirent);
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if (retval)
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return retval;
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t->det_checksum = ext2fs_cpu_to_le32(crc);
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return 0;
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}
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errcode_t ext2fs_dx_csum(ext2_filsys fs, ext2_ino_t inum,
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struct ext2_dir_entry *dirent,
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__u32 *crc, struct ext2_dx_tail **ret_t)
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{
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errcode_t retval;
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char *buf = (char *)dirent;
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int size;
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__u32 gen, dummy_csum = 0;
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struct ext2_inode inode;
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struct ext2_dx_tail *t;
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struct ext2_dx_countlimit *c;
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int count_offset, limit, count;
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retval = __get_dx_countlimit(fs, dirent, &c, &count_offset, 1);
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if (retval)
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return retval;
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limit = ext2fs_le16_to_cpu(c->limit);
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count = ext2fs_le16_to_cpu(c->count);
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if (count_offset + (limit * sizeof(struct ext2_dx_entry)) >
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fs->blocksize - sizeof(struct ext2_dx_tail))
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return EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
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/* htree structs are accessed in LE order */
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t = (struct ext2_dx_tail *)(((struct ext2_dx_entry *)c) + limit);
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size = count_offset + (count * sizeof(struct ext2_dx_entry));
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retval = ext2fs_read_inode(fs, inum, &inode);
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if (retval)
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return retval;
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inum = ext2fs_cpu_to_le32(inum);
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gen = ext2fs_cpu_to_le32(inode.i_generation);
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*crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&inum,
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sizeof(inum));
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*crc = ext2fs_crc32c_le(*crc, (unsigned char *)&gen, sizeof(gen));
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*crc = ext2fs_crc32c_le(*crc, (unsigned char *)buf, size);
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*crc = ext2fs_crc32c_le(*crc, (unsigned char *)t, 4);
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*crc = ext2fs_crc32c_le(*crc, (unsigned char *)&dummy_csum, 4);
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if (ret_t)
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*ret_t = t;
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return 0;
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}
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static int ext2fs_dx_csum_verify(ext2_filsys fs, ext2_ino_t inum,
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struct ext2_dir_entry *dirent)
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{
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__u32 calculated;
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errcode_t retval;
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struct ext2_dx_tail *t;
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retval = ext2fs_dx_csum(fs, inum, dirent, &calculated, &t);
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if (retval)
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return 0;
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return ext2fs_le32_to_cpu(t->dt_checksum) == calculated;
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}
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static errcode_t ext2fs_dx_csum_set(ext2_filsys fs, ext2_ino_t inum,
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struct ext2_dir_entry *dirent)
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{
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__u32 crc;
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errcode_t retval = 0;
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struct ext2_dx_tail *t;
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retval = ext2fs_dx_csum(fs, inum, dirent, &crc, &t);
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if (retval)
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return retval;
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t->dt_checksum = ext2fs_cpu_to_le32(crc);
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return retval;
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}
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int ext2fs_dir_block_csum_verify(ext2_filsys fs, ext2_ino_t inum,
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struct ext2_dir_entry *dirent)
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{
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if (!ext2fs_has_feature_metadata_csum(fs->super))
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return 1;
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if (__get_dirent_tail(fs, dirent, NULL, 1) == 0)
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return ext2fs_dirent_csum_verify(fs, inum, dirent);
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if (__get_dx_countlimit(fs, dirent, NULL, NULL, 1) == 0)
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return ext2fs_dx_csum_verify(fs, inum, dirent);
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return 0;
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}
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errcode_t ext2fs_dir_block_csum_set(ext2_filsys fs, ext2_ino_t inum,
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struct ext2_dir_entry *dirent)
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{
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if (!ext2fs_has_feature_metadata_csum(fs->super))
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return 0;
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if (__get_dirent_tail(fs, dirent, NULL, 1) == 0)
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return ext2fs_dirent_csum_set(fs, inum, dirent);
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if (__get_dx_countlimit(fs, dirent, NULL, NULL, 1) == 0)
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return ext2fs_dx_csum_set(fs, inum, dirent);
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if (fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS)
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return 0;
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return EXT2_ET_DIR_NO_SPACE_FOR_CSUM;
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}
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|
|
#define EXT3_EXTENT_TAIL_OFFSET(hdr) (sizeof(struct ext3_extent_header) + \
|
|
(sizeof(struct ext3_extent) * ext2fs_le16_to_cpu((hdr)->eh_max)))
|
|
|
|
static struct ext3_extent_tail *get_extent_tail(struct ext3_extent_header *h)
|
|
{
|
|
return (struct ext3_extent_tail *)(((char *)h) +
|
|
EXT3_EXTENT_TAIL_OFFSET(h));
|
|
}
|
|
|
|
static errcode_t ext2fs_extent_block_csum(ext2_filsys fs, ext2_ino_t inum,
|
|
struct ext3_extent_header *eh,
|
|
__u32 *crc)
|
|
{
|
|
int size;
|
|
__u32 gen;
|
|
errcode_t retval;
|
|
struct ext2_inode inode;
|
|
|
|
size = EXT3_EXTENT_TAIL_OFFSET(eh) + offsetof(struct ext3_extent_tail,
|
|
et_checksum);
|
|
|
|
retval = ext2fs_read_inode(fs, inum, &inode);
|
|
if (retval)
|
|
return retval;
|
|
inum = ext2fs_cpu_to_le32(inum);
|
|
gen = ext2fs_cpu_to_le32(inode.i_generation);
|
|
*crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&inum,
|
|
sizeof(inum));
|
|
*crc = ext2fs_crc32c_le(*crc, (unsigned char *)&gen, sizeof(gen));
|
|
*crc = ext2fs_crc32c_le(*crc, (unsigned char *)eh, size);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int ext2fs_extent_block_csum_verify(ext2_filsys fs, ext2_ino_t inum,
|
|
struct ext3_extent_header *eh)
|
|
{
|
|
errcode_t retval;
|
|
__u32 provided, calculated;
|
|
struct ext3_extent_tail *t = get_extent_tail(eh);
|
|
|
|
/*
|
|
* The extent tree structures are accessed in LE order, so we must
|
|
* swap the checksum bytes here.
|
|
*/
|
|
if (!ext2fs_has_feature_metadata_csum(fs->super))
|
|
return 1;
|
|
|
|
provided = ext2fs_le32_to_cpu(t->et_checksum);
|
|
retval = ext2fs_extent_block_csum(fs, inum, eh, &calculated);
|
|
if (retval)
|
|
return 0;
|
|
|
|
return provided == calculated;
|
|
}
|
|
|
|
errcode_t ext2fs_extent_block_csum_set(ext2_filsys fs, ext2_ino_t inum,
|
|
struct ext3_extent_header *eh)
|
|
{
|
|
errcode_t retval;
|
|
__u32 crc;
|
|
struct ext3_extent_tail *t = get_extent_tail(eh);
|
|
|
|
if (!ext2fs_has_feature_metadata_csum(fs->super))
|
|
return 0;
|
|
|
|
/*
|
|
* The extent tree structures are accessed in LE order, so we must
|
|
* swap the checksum bytes here.
|
|
*/
|
|
retval = ext2fs_extent_block_csum(fs, inum, eh, &crc);
|
|
if (retval)
|
|
return retval;
|
|
t->et_checksum = ext2fs_cpu_to_le32(crc);
|
|
return retval;
|
|
}
|
|
|
|
int ext2fs_inode_bitmap_csum_verify(ext2_filsys fs, dgrp_t group,
|
|
char *bitmap, int size)
|
|
{
|
|
struct ext4_group_desc *gdp = (struct ext4_group_desc *)
|
|
ext2fs_group_desc(fs, fs->group_desc, group);
|
|
__u32 provided, calculated;
|
|
|
|
if (!ext2fs_has_feature_metadata_csum(fs->super))
|
|
return 1;
|
|
provided = gdp->bg_inode_bitmap_csum_lo;
|
|
calculated = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)bitmap,
|
|
size);
|
|
if (EXT2_DESC_SIZE(fs->super) >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
|
|
provided |= (__u32)gdp->bg_inode_bitmap_csum_hi << 16;
|
|
else
|
|
calculated &= 0xFFFF;
|
|
|
|
return provided == calculated;
|
|
}
|
|
|
|
errcode_t ext2fs_inode_bitmap_csum_set(ext2_filsys fs, dgrp_t group,
|
|
char *bitmap, int size)
|
|
{
|
|
__u32 crc;
|
|
struct ext4_group_desc *gdp = (struct ext4_group_desc *)
|
|
ext2fs_group_desc(fs, fs->group_desc, group);
|
|
|
|
if (!ext2fs_has_feature_metadata_csum(fs->super))
|
|
return 0;
|
|
|
|
crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)bitmap, size);
|
|
gdp->bg_inode_bitmap_csum_lo = crc & 0xFFFF;
|
|
if (EXT2_DESC_SIZE(fs->super) >= EXT4_BG_INODE_BITMAP_CSUM_HI_END)
|
|
gdp->bg_inode_bitmap_csum_hi = crc >> 16;
|
|
|
|
return 0;
|
|
}
|
|
|
|
int ext2fs_block_bitmap_csum_verify(ext2_filsys fs, dgrp_t group,
|
|
char *bitmap, int size)
|
|
{
|
|
struct ext4_group_desc *gdp = (struct ext4_group_desc *)
|
|
ext2fs_group_desc(fs, fs->group_desc, group);
|
|
__u32 provided, calculated;
|
|
|
|
if (!ext2fs_has_feature_metadata_csum(fs->super))
|
|
return 1;
|
|
provided = gdp->bg_block_bitmap_csum_lo;
|
|
calculated = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)bitmap,
|
|
size);
|
|
if (EXT2_DESC_SIZE(fs->super) >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_LOCATION)
|
|
provided |= (__u32)gdp->bg_block_bitmap_csum_hi << 16;
|
|
else
|
|
calculated &= 0xFFFF;
|
|
|
|
return provided == calculated;
|
|
}
|
|
|
|
errcode_t ext2fs_block_bitmap_csum_set(ext2_filsys fs, dgrp_t group,
|
|
char *bitmap, int size)
|
|
{
|
|
__u32 crc;
|
|
struct ext4_group_desc *gdp = (struct ext4_group_desc *)
|
|
ext2fs_group_desc(fs, fs->group_desc, group);
|
|
|
|
if (!ext2fs_has_feature_metadata_csum(fs->super))
|
|
return 0;
|
|
|
|
crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)bitmap, size);
|
|
gdp->bg_block_bitmap_csum_lo = crc & 0xFFFF;
|
|
if (EXT2_DESC_SIZE(fs->super) >= EXT4_BG_BLOCK_BITMAP_CSUM_HI_LOCATION)
|
|
gdp->bg_block_bitmap_csum_hi = crc >> 16;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static errcode_t ext2fs_inode_csum(ext2_filsys fs, ext2_ino_t inum,
|
|
struct ext2_inode_large *inode,
|
|
__u32 *crc, int has_hi)
|
|
{
|
|
__u32 gen;
|
|
struct ext2_inode_large *desc = inode;
|
|
size_t size = EXT2_INODE_SIZE(fs->super);
|
|
__u16 old_lo;
|
|
__u16 old_hi = 0;
|
|
|
|
old_lo = inode->i_checksum_lo;
|
|
inode->i_checksum_lo = 0;
|
|
if (has_hi) {
|
|
old_hi = inode->i_checksum_hi;
|
|
inode->i_checksum_hi = 0;
|
|
}
|
|
|
|
inum = ext2fs_cpu_to_le32(inum);
|
|
gen = inode->i_generation;
|
|
*crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&inum,
|
|
sizeof(inum));
|
|
*crc = ext2fs_crc32c_le(*crc, (unsigned char *)&gen, sizeof(gen));
|
|
*crc = ext2fs_crc32c_le(*crc, (unsigned char *)desc, size);
|
|
|
|
inode->i_checksum_lo = old_lo;
|
|
if (has_hi)
|
|
inode->i_checksum_hi = old_hi;
|
|
return 0;
|
|
}
|
|
|
|
int ext2fs_inode_csum_verify(ext2_filsys fs, ext2_ino_t inum,
|
|
struct ext2_inode_large *inode)
|
|
{
|
|
errcode_t retval;
|
|
__u32 provided, calculated;
|
|
unsigned int i, has_hi;
|
|
char *cp;
|
|
|
|
if (!ext2fs_has_feature_metadata_csum(fs->super))
|
|
return 1;
|
|
|
|
has_hi = (EXT2_INODE_SIZE(fs->super) > EXT2_GOOD_OLD_INODE_SIZE &&
|
|
inode->i_extra_isize >= EXT4_INODE_CSUM_HI_EXTRA_END);
|
|
|
|
provided = ext2fs_le16_to_cpu(inode->i_checksum_lo);
|
|
retval = ext2fs_inode_csum(fs, inum, inode, &calculated, has_hi);
|
|
if (retval)
|
|
return 0;
|
|
if (has_hi) {
|
|
__u32 hi = ext2fs_le16_to_cpu(inode->i_checksum_hi);
|
|
provided |= hi << 16;
|
|
} else
|
|
calculated &= 0xFFFF;
|
|
|
|
if (provided == calculated)
|
|
return 1;
|
|
|
|
/*
|
|
* If the checksum didn't match, it's possible it was due to
|
|
* the inode being all zero's. It's unlikely this is the
|
|
* case, but it can happen. So check for it here. (We only
|
|
* check the base inode since that's good enough, and it's not
|
|
* worth the bother to figure out how much of the extended
|
|
* inode, if any, is present.)
|
|
*/
|
|
for (cp = (char *) inode, i = 0;
|
|
i < sizeof(struct ext2_inode);
|
|
cp++, i++)
|
|
if (*cp)
|
|
return 0;
|
|
return 1; /* Inode must have been all zero's */
|
|
}
|
|
|
|
errcode_t ext2fs_inode_csum_set(ext2_filsys fs, ext2_ino_t inum,
|
|
struct ext2_inode_large *inode)
|
|
{
|
|
errcode_t retval;
|
|
__u32 crc;
|
|
int has_hi;
|
|
|
|
if (!ext2fs_has_feature_metadata_csum(fs->super))
|
|
return 0;
|
|
|
|
has_hi = (EXT2_INODE_SIZE(fs->super) > EXT2_GOOD_OLD_INODE_SIZE &&
|
|
inode->i_extra_isize >= EXT4_INODE_CSUM_HI_EXTRA_END);
|
|
|
|
retval = ext2fs_inode_csum(fs, inum, inode, &crc, has_hi);
|
|
if (retval)
|
|
return retval;
|
|
inode->i_checksum_lo = ext2fs_cpu_to_le16(crc & 0xFFFF);
|
|
if (has_hi)
|
|
inode->i_checksum_hi = ext2fs_cpu_to_le16(crc >> 16);
|
|
return 0;
|
|
}
|
|
|
|
__u16 ext2fs_group_desc_csum(ext2_filsys fs, dgrp_t group)
|
|
{
|
|
struct ext2_group_desc *desc = ext2fs_group_desc(fs, fs->group_desc,
|
|
group);
|
|
size_t offset, size = EXT2_DESC_SIZE(fs->super);
|
|
__u16 crc = 0;
|
|
#ifdef WORDS_BIGENDIAN
|
|
struct ext4_group_desc swabdesc;
|
|
size_t save_size = size;
|
|
const size_t ext4_bg_size = sizeof(struct ext4_group_desc);
|
|
struct ext2_group_desc *save_desc = desc;
|
|
|
|
/* Have to swab back to little-endian to do the checksum */
|
|
if (size > ext4_bg_size)
|
|
size = ext4_bg_size;
|
|
memcpy(&swabdesc, desc, size);
|
|
ext2fs_swap_group_desc2(fs, (struct ext2_group_desc *) &swabdesc);
|
|
desc = (struct ext2_group_desc *) &swabdesc;
|
|
group = ext2fs_swab32(group);
|
|
#endif
|
|
|
|
if (ext2fs_has_feature_metadata_csum(fs->super)) {
|
|
/* new metadata csum code */
|
|
__u16 old_crc;
|
|
__u32 crc32;
|
|
|
|
old_crc = desc->bg_checksum;
|
|
desc->bg_checksum = 0;
|
|
crc32 = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&group,
|
|
sizeof(group));
|
|
crc32 = ext2fs_crc32c_le(crc32, (unsigned char *)desc,
|
|
size);
|
|
desc->bg_checksum = old_crc;
|
|
#ifdef WORDS_BIGENDIAN
|
|
if (save_size > ext4_bg_size)
|
|
crc32 = ext2fs_crc32c_le(crc32,
|
|
(unsigned char *)save_desc + ext4_bg_size,
|
|
save_size - ext4_bg_size);
|
|
#endif
|
|
crc = crc32 & 0xFFFF;
|
|
goto out;
|
|
}
|
|
|
|
/* old crc16 code */
|
|
offset = offsetof(struct ext2_group_desc, bg_checksum);
|
|
crc = ext2fs_crc16(~0, fs->super->s_uuid,
|
|
sizeof(fs->super->s_uuid));
|
|
crc = ext2fs_crc16(crc, &group, sizeof(group));
|
|
crc = ext2fs_crc16(crc, desc, offset);
|
|
offset += sizeof(desc->bg_checksum); /* skip checksum */
|
|
/* for checksum of struct ext4_group_desc do the rest...*/
|
|
if (offset < size) {
|
|
crc = ext2fs_crc16(crc, (char *)desc + offset,
|
|
size - offset);
|
|
}
|
|
#ifdef WORDS_BIGENDIAN
|
|
/*
|
|
* If the size of the bg descriptor is greater than 64
|
|
* bytes, which is the size of the traditional ext4 bg
|
|
* descriptor, checksum the rest of the descriptor here
|
|
*/
|
|
if (save_size > ext4_bg_size)
|
|
crc = ext2fs_crc16(crc, (char *)save_desc + ext4_bg_size,
|
|
save_size - ext4_bg_size);
|
|
#endif
|
|
|
|
out:
|
|
return crc;
|
|
}
|
|
|
|
int ext2fs_group_desc_csum_verify(ext2_filsys fs, dgrp_t group)
|
|
{
|
|
if (ext2fs_has_group_desc_csum(fs) &&
|
|
(ext2fs_bg_checksum(fs, group) !=
|
|
ext2fs_group_desc_csum(fs, group)))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
void ext2fs_group_desc_csum_set(ext2_filsys fs, dgrp_t group)
|
|
{
|
|
if (!ext2fs_has_group_desc_csum(fs))
|
|
return;
|
|
|
|
/* ext2fs_bg_checksum_set() sets the actual checksum field but
|
|
* does not calculate the checksum itself. */
|
|
ext2fs_bg_checksum_set(fs, group, ext2fs_group_desc_csum(fs, group));
|
|
}
|
|
|
|
static __u32 find_last_inode_ingrp(ext2fs_inode_bitmap bitmap,
|
|
__u32 inodes_per_grp, dgrp_t grp_no)
|
|
{
|
|
ext2_ino_t i, start_ino, end_ino;
|
|
|
|
start_ino = grp_no * inodes_per_grp + 1;
|
|
end_ino = start_ino + inodes_per_grp - 1;
|
|
|
|
for (i = end_ino; i >= start_ino; i--) {
|
|
if (ext2fs_fast_test_inode_bitmap2(bitmap, i))
|
|
return i - start_ino + 1;
|
|
}
|
|
return inodes_per_grp;
|
|
}
|
|
|
|
/* update the bitmap flags, set the itable high watermark, and calculate
|
|
* checksums for the group descriptors */
|
|
errcode_t ext2fs_set_gdt_csum(ext2_filsys fs)
|
|
{
|
|
struct ext2_super_block *sb = fs->super;
|
|
int dirty = 0;
|
|
dgrp_t i;
|
|
|
|
if (!fs->inode_map)
|
|
return EXT2_ET_NO_INODE_BITMAP;
|
|
|
|
if (!ext2fs_has_group_desc_csum(fs))
|
|
return 0;
|
|
|
|
for (i = 0; i < fs->group_desc_count; i++) {
|
|
__u32 old_csum = ext2fs_bg_checksum(fs, i);
|
|
__u32 old_unused = ext2fs_bg_itable_unused(fs, i);
|
|
__u32 old_flags = ext2fs_bg_flags(fs, i);
|
|
__u32 old_free_inodes_count = ext2fs_bg_free_inodes_count(fs, i);
|
|
__u32 old_free_blocks_count = ext2fs_bg_free_blocks_count(fs, i);
|
|
|
|
if (old_free_blocks_count == sb->s_blocks_per_group &&
|
|
i != fs->group_desc_count - 1)
|
|
ext2fs_bg_flags_set(fs, i, EXT2_BG_BLOCK_UNINIT);
|
|
|
|
if (old_free_inodes_count == sb->s_inodes_per_group) {
|
|
ext2fs_bg_flags_set(fs, i, EXT2_BG_INODE_UNINIT);
|
|
ext2fs_bg_itable_unused_set(fs, i, sb->s_inodes_per_group);
|
|
} else {
|
|
int unused =
|
|
sb->s_inodes_per_group -
|
|
find_last_inode_ingrp(fs->inode_map,
|
|
sb->s_inodes_per_group, i);
|
|
|
|
ext2fs_bg_flags_clear(fs, i, EXT2_BG_INODE_UNINIT);
|
|
ext2fs_bg_itable_unused_set(fs, i, unused);
|
|
}
|
|
|
|
ext2fs_group_desc_csum_set(fs, i);
|
|
if (old_flags != ext2fs_bg_flags(fs, i))
|
|
dirty = 1;
|
|
if (old_unused != ext2fs_bg_itable_unused(fs, i))
|
|
dirty = 1;
|
|
if (old_csum != ext2fs_bg_checksum(fs, i))
|
|
dirty = 1;
|
|
}
|
|
if (dirty)
|
|
ext2fs_mark_super_dirty(fs);
|
|
return 0;
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
#include "e2p/e2p.h"
|
|
|
|
void print_csum(const char *msg, ext2_filsys fs, dgrp_t group)
|
|
{
|
|
__u16 crc1, crc2, crc3;
|
|
dgrp_t swabgroup;
|
|
struct ext2_group_desc *desc = ext2fs_group_desc(fs, fs->group_desc,
|
|
group);
|
|
size_t size = EXT2_DESC_SIZE(fs->super);
|
|
struct ext2_super_block *sb = fs->super;
|
|
int offset = offsetof(struct ext2_group_desc, bg_checksum);
|
|
#ifdef WORDS_BIGENDIAN
|
|
struct ext4_group_desc swabdesc;
|
|
struct ext2_group_desc *save_desc = desc;
|
|
const size_t ext4_bg_size = sizeof(struct ext4_group_desc);
|
|
size_t save_size = size;
|
|
#endif
|
|
|
|
#ifdef WORDS_BIGENDIAN
|
|
/* Have to swab back to little-endian to do the checksum */
|
|
if (size > ext4_bg_size)
|
|
size = ext4_bg_size;
|
|
memcpy(&swabdesc, desc, size);
|
|
ext2fs_swap_group_desc2(fs, (struct ext2_group_desc *) &swabdesc);
|
|
desc = (struct ext2_group_desc *) &swabdesc;
|
|
|
|
swabgroup = ext2fs_swab32(group);
|
|
#else
|
|
swabgroup = group;
|
|
#endif
|
|
|
|
crc1 = ext2fs_crc16(~0, sb->s_uuid, sizeof(fs->super->s_uuid));
|
|
crc2 = ext2fs_crc16(crc1, &swabgroup, sizeof(swabgroup));
|
|
crc3 = ext2fs_crc16(crc2, desc, offset);
|
|
offset += sizeof(desc->bg_checksum); /* skip checksum */
|
|
/* for checksum of struct ext4_group_desc do the rest...*/
|
|
if (offset < size)
|
|
crc3 = ext2fs_crc16(crc3, (char *)desc + offset, size - offset);
|
|
#ifdef WORDS_BIGENDIAN
|
|
if (save_size > ext4_bg_size)
|
|
crc3 = ext2fs_crc16(crc3, (char *)save_desc + ext4_bg_size,
|
|
save_size - ext4_bg_size);
|
|
#endif
|
|
|
|
printf("%s UUID %s=%04x, grp %u=%04x: %04x=%04x\n",
|
|
msg, e2p_uuid2str(sb->s_uuid), crc1, group, crc2, crc3,
|
|
ext2fs_group_desc_csum(fs, group));
|
|
}
|
|
|
|
unsigned char sb_uuid[16] = { 0x4f, 0x25, 0xe8, 0xcf, 0xe7, 0x97, 0x48, 0x23,
|
|
0xbe, 0xfa, 0xa7, 0x88, 0x4b, 0xae, 0xec, 0xdb };
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
struct ext2_super_block param;
|
|
errcode_t retval;
|
|
ext2_filsys fs;
|
|
int i;
|
|
__u16 csum1, csum2, csum_known = 0xd3a4;
|
|
|
|
memset(¶m, 0, sizeof(param));
|
|
ext2fs_blocks_count_set(¶m, 32768);
|
|
#if 0
|
|
param.s_feature_incompat |= EXT4_FEATURE_INCOMPAT_64BIT;
|
|
param.s_desc_size = 128;
|
|
csum_known = 0x5b6e;
|
|
#endif
|
|
|
|
retval = ext2fs_initialize("test fs", EXT2_FLAG_64BITS, ¶m,
|
|
test_io_manager, &fs);
|
|
if (retval) {
|
|
com_err("setup", retval,
|
|
"While initializing filesystem");
|
|
exit(1);
|
|
}
|
|
memcpy(fs->super->s_uuid, sb_uuid, 16);
|
|
fs->super->s_feature_ro_compat = EXT4_FEATURE_RO_COMPAT_GDT_CSUM;
|
|
|
|
for (i=0; i < fs->group_desc_count; i++) {
|
|
ext2fs_block_bitmap_loc_set(fs, i, 124);
|
|
ext2fs_inode_bitmap_loc_set(fs, i, 125);
|
|
ext2fs_inode_table_loc_set(fs, i, 126);
|
|
ext2fs_bg_free_blocks_count_set(fs, i, 31119);
|
|
ext2fs_bg_free_inodes_count_set(fs, i, 15701);
|
|
ext2fs_bg_used_dirs_count_set(fs, i, 2);
|
|
ext2fs_bg_flags_zap(fs, i);
|
|
};
|
|
|
|
csum1 = ext2fs_group_desc_csum(fs, 0);
|
|
print_csum("csum0000", fs, 0);
|
|
|
|
if (csum1 != csum_known) {
|
|
printf("checksum for group 0 should be %04x\n", csum_known);
|
|
exit(1);
|
|
}
|
|
csum2 = ext2fs_group_desc_csum(fs, 1);
|
|
print_csum("csum0001", fs, 1);
|
|
if (csum1 == csum2) {
|
|
printf("checksums for different groups shouldn't match\n");
|
|
exit(1);
|
|
}
|
|
csum2 = ext2fs_group_desc_csum(fs, 2);
|
|
print_csum("csumffff", fs, 2);
|
|
if (csum1 == csum2) {
|
|
printf("checksums for different groups shouldn't match\n");
|
|
exit(1);
|
|
}
|
|
ext2fs_bg_checksum_set(fs, 0, csum1);
|
|
csum2 = ext2fs_group_desc_csum(fs, 0);
|
|
print_csum("csum_set", fs, 0);
|
|
if (csum1 != csum2) {
|
|
printf("checksums should not depend on checksum field\n");
|
|
exit(1);
|
|
}
|
|
if (!ext2fs_group_desc_csum_verify(fs, 0)) {
|
|
printf("checksums should verify against gd_checksum\n");
|
|
exit(1);
|
|
}
|
|
memset(fs->super->s_uuid, 0x30, sizeof(fs->super->s_uuid));
|
|
print_csum("new_uuid", fs, 0);
|
|
if (ext2fs_group_desc_csum_verify(fs, 0) != 0) {
|
|
printf("checksums for different filesystems shouldn't match\n");
|
|
exit(1);
|
|
}
|
|
csum1 = ext2fs_group_desc_csum(fs, 0);
|
|
ext2fs_bg_checksum_set(fs, 0, csum1);
|
|
print_csum("csum_new", fs, 0);
|
|
ext2fs_bg_free_blocks_count_set(fs, 0, 1);
|
|
csum2 = ext2fs_group_desc_csum(fs, 0);
|
|
print_csum("csum_blk", fs, 0);
|
|
if (csum1 == csum2) {
|
|
printf("checksums for different data shouldn't match\n");
|
|
exit(1);
|
|
}
|
|
ext2fs_free(fs);
|
|
|
|
return 0;
|
|
}
|
|
#endif
|