| /* |
| * csum.c --- checksumming of ext3 structures |
| * |
| * Copyright (C) 2006 Cluster File Systems, Inc. |
| * Copyright (C) 2006, 2007 by Andreas Dilger <adilger@clusterfs.com> |
| * |
| * %Begin-Header% |
| * This file may be redistributed under the terms of the GNU Library |
| * General Public License, version 2. |
| * %End-Header% |
| */ |
| |
| #include "config.h" |
| #if HAVE_SYS_TYPES_H |
| #include <sys/types.h> |
| #endif |
| |
| #include "ext2_fs.h" |
| #include "ext2fs.h" |
| #include "crc16.h" |
| #include <assert.h> |
| |
| #ifndef offsetof |
| #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER) |
| #endif |
| |
| #ifdef DEBUG |
| #define STATIC |
| #else |
| #define STATIC static |
| #endif |
| |
| void ext2fs_init_csum_seed(ext2_filsys fs) |
| { |
| if (ext2fs_has_feature_csum_seed(fs->super)) |
| fs->csum_seed = fs->super->s_checksum_seed; |
| else if (ext2fs_has_feature_metadata_csum(fs->super)) |
| fs->csum_seed = ext2fs_crc32c_le(~0, fs->super->s_uuid, |
| sizeof(fs->super->s_uuid)); |
| } |
| |
| static __u32 ext2fs_mmp_csum(ext2_filsys fs, struct mmp_struct *mmp) |
| { |
| int offset = offsetof(struct mmp_struct, mmp_checksum); |
| |
| return ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)mmp, offset); |
| } |
| |
| int ext2fs_mmp_csum_verify(ext2_filsys fs, struct mmp_struct *mmp) |
| { |
| __u32 calculated; |
| |
| if (!ext2fs_has_feature_metadata_csum(fs->super)) |
| return 1; |
| |
| calculated = ext2fs_mmp_csum(fs, mmp); |
| |
| return ext2fs_le32_to_cpu(mmp->mmp_checksum) == calculated; |
| } |
| |
| errcode_t ext2fs_mmp_csum_set(ext2_filsys fs, struct mmp_struct *mmp) |
| { |
| __u32 crc; |
| |
| if (!ext2fs_has_feature_metadata_csum(fs->super)) |
| return 0; |
| |
| crc = ext2fs_mmp_csum(fs, mmp); |
| mmp->mmp_checksum = ext2fs_cpu_to_le32(crc); |
| |
| return 0; |
| } |
| |
| int ext2fs_verify_csum_type(ext2_filsys fs, struct ext2_super_block *sb) |
| { |
| if (!ext2fs_has_feature_metadata_csum(fs->super)) |
| return 1; |
| |
| return sb->s_checksum_type == EXT2_CRC32C_CHKSUM; |
| } |
| |
| static __u32 ext2fs_superblock_csum(ext2_filsys fs EXT2FS_ATTR((unused)), |
| struct ext2_super_block *sb) |
| { |
| int offset = offsetof(struct ext2_super_block, s_checksum); |
| |
| return ext2fs_crc32c_le(~0, (unsigned char *)sb, offset); |
| } |
| |
| /* NOTE: The input to this function MUST be in LE order */ |
| int ext2fs_superblock_csum_verify(ext2_filsys fs, struct ext2_super_block *sb) |
| { |
| __u32 flag, calculated; |
| |
| if (fs->flags & EXT2_FLAG_SWAP_BYTES) |
| flag = EXT4_FEATURE_RO_COMPAT_METADATA_CSUM; |
| else |
| flag = ext2fs_cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM); |
| |
| if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super, flag)) |
| return 1; |
| |
| calculated = ext2fs_superblock_csum(fs, sb); |
| |
| return ext2fs_le32_to_cpu(sb->s_checksum) == calculated; |
| } |
| |
| /* NOTE: The input to this function MUST be in LE order */ |
| errcode_t ext2fs_superblock_csum_set(ext2_filsys fs, |
| struct ext2_super_block *sb) |
| { |
| __u32 flag, crc; |
| |
| if (fs->flags & EXT2_FLAG_SWAP_BYTES) |
| flag = EXT4_FEATURE_RO_COMPAT_METADATA_CSUM; |
| else |
| flag = ext2fs_cpu_to_le32(EXT4_FEATURE_RO_COMPAT_METADATA_CSUM); |
| |
| if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super, flag)) |
| return 0; |
| |
| crc = ext2fs_superblock_csum(fs, sb); |
| sb->s_checksum = ext2fs_cpu_to_le32(crc); |
| |
| return 0; |
| } |
| |
| static errcode_t ext2fs_ext_attr_block_csum(ext2_filsys fs, |
| ext2_ino_t inum EXT2FS_ATTR((unused)), |
| blk64_t block, |
| struct ext2_ext_attr_header *hdr, |
| __u32 *crc) |
| { |
| char *buf = (char *)hdr; |
| __u32 old_crc = hdr->h_checksum; |
| |
| hdr->h_checksum = 0; |
| block = ext2fs_cpu_to_le64(block); |
| *crc = ext2fs_crc32c_le(fs->csum_seed, (unsigned char *)&block, |
| sizeof(block)); |
| *crc = ext2fs_crc32c_le(*crc, (unsigned char *)buf, fs->blocksize); |
| hdr->h_checksum = old_crc; |
| |
| return 0; |
| } |
| |
| int ext2fs_ext_attr_block_csum_verify(ext2_filsys fs, ext2_ino_t inum, |
| blk64_t block, |
| struct ext2_ext_attr_header *hdr) |
| { |
| __u32 calculated; |
| errcode_t retval; |
| |
| if (!ext2fs_has_feature_metadata_csum(fs->super)) |
| return 1; |
| |
| retval = ext2fs_ext_attr_block_csum(fs, inum, block, hdr, &calculated); |
| if (retval) |
| return 0; |
| |
| return ext2fs_le32_to_cpu(hdr->h_checksum) == calculated; |
| } |
| |
| errcode_t ext2fs_ext_attr_block_csum_set(ext2_filsys fs, ext2_ino_t inum, |
| blk64_t block, |
| struct ext2_ext_attr_header *hdr) |
| { |
| errcode_t retval; |
| __u32 crc; |
| |
| if (!ext2fs_has_feature_metadata_csum(fs->super)) |
| return 0; |
| |
| retval = ext2fs_ext_attr_block_csum(fs, inum, block, hdr, &crc); |
| if (retval) |
| return retval; |
| hdr->h_checksum = ext2fs_cpu_to_le32(crc); |
| return 0; |
| } |
| |
| static __u16 do_nothing16(__u16 x) |
| { |
| return x; |
| } |
| |
| static __u16 disk_to_host16(__u16 x) |
| { |
| return ext2fs_le16_to_cpu(x); |
| } |
| |
| static errcode_t __get_dx_countlimit(ext2_filsys fs, |
| struct ext2_dir_entry *dirent, |
| struct ext2_dx_countlimit **cc, |
| int *offset, |
| int need_swab) |
| { |
| struct ext2_dir_entry *dp; |
| struct ext2_dx_root_info *root; |
| struct ext2_dx_countlimit *c; |
| int count_offset, max_sane_entries; |
| unsigned int rec_len; |
| __u16 (*translate)(__u16) = (need_swab ? disk_to_host16 : do_nothing16); |
| |
| rec_len = translate(dirent->rec_len); |
| |
| if (rec_len == fs->blocksize && translate(dirent->name_len) == 0) |
| count_offset = 8; |
| else if (rec_len == 12) { |
| dp = (struct ext2_dir_entry *)(((char *)dirent) + rec_len); |
| rec_len = translate(dp->rec_len); |
| if (rec_len != fs->blocksize - 12) |
| return EXT2_ET_DB_NOT_FOUND; |
| root = (struct ext2_dx_root_info *)(((char *)dp + 12)); |
| if (root->reserved_zero || |
| root->info_length != sizeof(struct ext2_dx_root_info)) |
| return EXT2_ET_DB_NOT_FOUND; |
| count_offset = 32; |
| } else |
| return EXT2_ET_DB_NOT_FOUND; |
| |
| c = (struct ext2_dx_countlimit *)(((char *)dirent) + count_offset); |
| max_sane_entries = (fs->blocksize - count_offset) / |
| sizeof(struct ext2_dx_entry); |
| if (ext2fs_le16_to_cpu(c->limit) > max_sane_entries || |
| ext2fs_le16_to_cpu(c->count) > max_sane_entries) |
| return EXT2_ET_DIR_NO_SPACE_FOR_CSUM; |
| |
| if (offset) |
| *offset = count_offset; |
| if (cc) |
| *cc = c; |
| |
| return 0; |
| } |
| |
| errcode_t ext2fs_get_dx_countlimit(ext2_filsys fs, |
| struct ext2_dir_entry *dirent, |
| struct ext2_dx_countlimit **cc, |
| int *offset) |
| { |
| return __get_dx_countlimit(fs, dirent, cc, offset, 0); |
| } |
| |
| void ext2fs_initialize_dirent_tail(ext2_filsys fs, |
| struct ext2_dir_entry_tail *t) |
| { |
| memset(t, 0, sizeof(struct ext2_dir_entry_tail)); |
| ext2fs_set_rec_len(fs, sizeof(struct ext2_dir_entry_tail), |
| (struct ext2_dir_entry *)t); |
| t->det_reserved_name_len = EXT2_DIR_NAME_LEN_CSUM; |
| } |
| |
| static errcode_t __get_dirent_tail(ext2_filsys fs, |
| struct ext2_dir_entry *dirent, |
| struct ext2_dir_entry_tail **tt, |
| int need_swab) |
| { |
| struct ext2_dir_entry *d; |
| void *top; |
| struct ext2_dir_entry_tail *t; |
| unsigned int rec_len; |
| errcode_t retval = 0; |
| __u16 (*translate)(__u16) = (need_swab ? disk_to_host16 : do_nothing16); |
| |
| d = dirent; |
| top = EXT2_DIRENT_TAIL(dirent, fs->blocksize); |
| |
| rec_len = translate(d->rec_len); |
| while (rec_len && !(rec_len & 0x3)) { |
| d = (struct ext2_dir_entry *)(((char *)d) + rec_len); |
| if ((void *)d >= top) |
| break; |
| rec_len = translate(d->rec_len); |
| } |
| |
| if (d != top) |
| return EXT2_ET_DIR_NO_SPACE_FOR_CSUM; |
| |
| t = (struct ext2_dir_entry_tail *)d; |
| if (t->det_reserved_zero1 || |
| translate(t->det_rec_len) != sizeof(struct ext2_dir_entry_tail) || |
| translate(t->det_reserved_name_len) != EXT2_DIR_NAME_LEN_CSUM) |
| return EXT2_ET_DIR_NO_SPACE_FOR_CSUM; |
| |
| if (tt) |
| *tt = t; |
| return retval; |
| } |
| |
| int ext2fs_dirent_has_tail(ext2_filsys fs, struct ext2_dir_entry *dirent) |
| { |
| return __get_dirent_tail(fs, dirent, NULL, 0) == 0; |
| } |
| |
| static errcode_t ext2fs_dirent_csum(ext2_filsys fs, ext2_ino_t inum, |
| struct ext2_dir_entry *dirent, __u32 *crc, |
| int size) |
| { |
| errcode_t retval; |
| char *buf = (char *)dirent; |
| __u32 gen; |
| struct ext2_inode inode; |
| |
| 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 *)buf, size); |
| |
| return 0; |
| } |
| |
| int ext2fs_dirent_csum_verify(ext2_filsys fs, ext2_ino_t inum, |
| struct ext2_dir_entry *dirent) |
| { |
| errcode_t retval; |
| __u32 calculated; |
| struct ext2_dir_entry_tail *t; |
| |
| retval = __get_dirent_tail(fs, dirent, &t, 1); |
| if (retval) |
| return 1; |
| |
| /* |
| * The checksum field is overlaid with the dirent->name field |
| * so the swapfs.c functions won't change the endianness. |
| */ |
| retval = ext2fs_dirent_csum(fs, inum, dirent, &calculated, |
| (char *)t - (char *)dirent); |
| if (retval) |
| return 0; |
| return ext2fs_le32_to_cpu(t->det_checksum) == calculated; |
| } |
| |
| static errcode_t ext2fs_dirent_csum_set(ext2_filsys fs, ext2_ino_t inum, |
| struct ext2_dir_entry *dirent) |
| { |
| errcode_t retval; |
| __u32 crc; |
| struct ext2_dir_entry_tail *t; |
| |
| retval = __get_dirent_tail(fs, dirent, &t, 1); |
| if (retval) |
| return retval; |
| |
| /* swapfs.c functions don't change the checksum endianness */ |
| retval = ext2fs_dirent_csum(fs, inum, dirent, &crc, |
| (char *)t - (char *)dirent); |
| if (retval) |
| return retval; |
| t->det_checksum = ext2fs_cpu_to_le32(crc); |
| return 0; |
| } |
| |
| static errcode_t ext2fs_dx_csum(ext2_filsys fs, ext2_ino_t inum, |
| struct ext2_dir_entry *dirent, |
| __u32 *crc, int count_offset, int count, |
| struct ext2_dx_tail *t) |
| { |
| errcode_t retval; |
| char *buf = (char *)dirent; |
| int size; |
| __u32 old_csum, gen; |
| struct ext2_inode inode; |
| |
| size = count_offset + (count * sizeof(struct ext2_dx_entry)); |
| old_csum = t->dt_checksum; |
| t->dt_checksum = 0; |
| |
| 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 *)buf, size); |
| *crc = ext2fs_crc32c_le(*crc, (unsigned char *)t, |
| sizeof(struct ext2_dx_tail)); |
| t->dt_checksum = old_csum; |
| |
| return 0; |
| } |
| |
| static int ext2fs_dx_csum_verify(ext2_filsys fs, ext2_ino_t inum, |
| struct ext2_dir_entry *dirent) |
| { |
| __u32 calculated; |
| errcode_t retval; |
| struct ext2_dx_countlimit *c; |
| struct ext2_dx_tail *t; |
| int count_offset, limit, count; |
| |
| retval = __get_dx_countlimit(fs, dirent, &c, &count_offset, 1); |
| if (retval) |
| return 1; |
| limit = ext2fs_le16_to_cpu(c->limit); |
| count = ext2fs_le16_to_cpu(c->count); |
| if (count_offset + (limit * sizeof(struct ext2_dx_entry)) > |
| fs->blocksize - sizeof(struct ext2_dx_tail)) |
| return 0; |
| /* htree structs are accessed in LE order */ |
| t = (struct ext2_dx_tail *)(((struct ext2_dx_entry *)c) + limit); |
| retval = ext2fs_dx_csum(fs, inum, dirent, &calculated, count_offset, |
| count, t); |
| if (retval) |
| return 0; |
| |
| return ext2fs_le32_to_cpu(t->dt_checksum) == calculated; |
| } |
| |
| static errcode_t ext2fs_dx_csum_set(ext2_filsys fs, ext2_ino_t inum, |
| struct ext2_dir_entry *dirent) |
| { |
| __u32 crc; |
| errcode_t retval = 0; |
| struct ext2_dx_countlimit *c; |
| struct ext2_dx_tail *t; |
| int count_offset, limit, count; |
| |
| retval = __get_dx_countlimit(fs, dirent, &c, &count_offset, 1); |
| if (retval) |
| return retval; |
| limit = ext2fs_le16_to_cpu(c->limit); |
| count = ext2fs_le16_to_cpu(c->count); |
| if (count_offset + (limit * sizeof(struct ext2_dx_entry)) > |
| fs->blocksize - sizeof(struct ext2_dx_tail)) |
| return EXT2_ET_DIR_NO_SPACE_FOR_CSUM; |
| t = (struct ext2_dx_tail *)(((struct ext2_dx_entry *)c) + limit); |
| |
| /* htree structs are accessed in LE order */ |
| retval = ext2fs_dx_csum(fs, inum, dirent, &crc, count_offset, count, t); |
| if (retval) |
| return retval; |
| t->dt_checksum = ext2fs_cpu_to_le32(crc); |
| return retval; |
| } |
| |
| int ext2fs_dir_block_csum_verify(ext2_filsys fs, ext2_ino_t inum, |
| struct ext2_dir_entry *dirent) |
| { |
| if (!ext2fs_has_feature_metadata_csum(fs->super)) |
| return 1; |
| |
| if (__get_dirent_tail(fs, dirent, NULL, 1) == 0) |
| return ext2fs_dirent_csum_verify(fs, inum, dirent); |
| if (__get_dx_countlimit(fs, dirent, NULL, NULL, 1) == 0) |
| return ext2fs_dx_csum_verify(fs, inum, dirent); |
| |
| return 0; |
| } |
| |
| errcode_t ext2fs_dir_block_csum_set(ext2_filsys fs, ext2_ino_t inum, |
| struct ext2_dir_entry *dirent) |
| { |
| if (!ext2fs_has_feature_metadata_csum(fs->super)) |
| return 0; |
| |
| if (__get_dirent_tail(fs, dirent, NULL, 1) == 0) |
| return ext2fs_dirent_csum_set(fs, inum, dirent); |
| if (__get_dx_countlimit(fs, dirent, NULL, NULL, 1) == 0) |
| return ext2fs_dx_csum_set(fs, inum, dirent); |
| |
| if (fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) |
| return 0; |
| return EXT2_ET_DIR_NO_SPACE_FOR_CSUM; |
| } |
| |
| #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 (fs->super->s_desc_size >= 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 (fs->super->s_desc_size >= 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 (fs->super->s_desc_size >= 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 (fs->super->s_desc_size >= 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 = fs->super->s_inode_size; |
| __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); |
| } |
| |
| return 0; |
| } |
| #endif |