e2fsprogs/debugfs/htree.c
Darrick J. Wong 81683c6a32 libext2fs: add checksums to the end of directory leaf nodes
Introduce small structures for recording directory tree checksums, and
some API changes to support writing out directory blocks with
checksums.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2012-08-02 17:27:43 -04:00

432 lines
11 KiB
C

/*
* htree.c --- hash tree routines
*
* Copyright (C) 2002 Theodore Ts'o. This file may be redistributed
* under the terms of the GNU Public License.
*/
#include "config.h"
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <time.h>
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <sys/types.h>
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#else
extern int optind;
extern char *optarg;
#endif
#include "debugfs.h"
#include "uuid/uuid.h"
#include "e2p/e2p.h"
static FILE *pager;
static void htree_dump_leaf_node(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode *inode,
struct ext2_dx_root_info * rootnode,
blk64_t blk, char *buf)
{
errcode_t errcode;
struct ext2_dir_entry *dirent;
int thislen, col = 0;
unsigned int offset = 0;
char name[EXT2_NAME_LEN + 1];
char tmp[EXT2_NAME_LEN + 64];
blk64_t pblk;
ext2_dirhash_t hash, minor_hash;
unsigned int rec_len;
int hash_alg;
int csum_size = 0;
if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
csum_size = sizeof(struct ext2_dir_entry_tail);
errcode = ext2fs_bmap2(fs, ino, inode, buf, 0, blk, 0, &pblk);
if (errcode) {
com_err("htree_dump_leaf_node", errcode,
"while mapping logical block %llu\n", blk);
return;
}
printf("Reading directory block %llu, phys %llu\n", blk, pblk);
errcode = ext2fs_read_dir_block4(current_fs, pblk, buf, 0, ino);
if (errcode) {
com_err("htree_dump_leaf_node", errcode,
"while reading block %llu (%llu)\n",
blk, pblk);
return;
}
hash_alg = rootnode->hash_version;
if ((hash_alg <= EXT2_HASH_TEA) &&
(fs->super->s_flags & EXT2_FLAGS_UNSIGNED_HASH))
hash_alg += 3;
while (offset < (fs->blocksize - csum_size)) {
dirent = (struct ext2_dir_entry *) (buf + offset);
errcode = ext2fs_get_rec_len(fs, dirent, &rec_len);
if (errcode) {
com_err("htree_dump_leaf_inode", errcode,
"while getting rec_len for block %lu",
(unsigned long) blk);
return;
}
if (((offset + rec_len) > fs->blocksize) ||
(rec_len < 8) ||
((rec_len % 4) != 0) ||
((((unsigned) dirent->name_len & 0xFF)+8) > rec_len)) {
fprintf(pager, "Corrupted directory block (%llu)!\n",
blk);
break;
}
thislen = dirent->name_len & 0xFF;
strncpy(name, dirent->name, thislen);
name[thislen] = '\0';
errcode = ext2fs_dirhash(hash_alg, name,
thislen, fs->super->s_hash_seed,
&hash, &minor_hash);
if (errcode)
com_err("htree_dump_leaf_node", errcode,
"while calculating hash");
snprintf(tmp, EXT2_NAME_LEN + 64, "%u 0x%08x-%08x (%d) %s ",
dirent->inode, hash, minor_hash, rec_len, name);
thislen = strlen(tmp);
if (col + thislen > 80) {
fprintf(pager, "\n");
col = 0;
}
fprintf(pager, "%s", tmp);
col += thislen;
offset += rec_len;
}
fprintf(pager, "\n");
}
static void htree_dump_int_block(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode *inode,
struct ext2_dx_root_info * rootnode,
blk64_t blk, char *buf, int level);
static void htree_dump_int_node(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode *inode,
struct ext2_dx_root_info * rootnode,
struct ext2_dx_entry *ent,
char *buf, int level)
{
struct ext2_dx_countlimit limit;
struct ext2_dx_entry e;
struct ext2_dx_tail *tail;
int hash, i;
int remainder;
limit = *((struct ext2_dx_countlimit *) ent);
limit.count = ext2fs_le16_to_cpu(limit.count);
limit.limit = ext2fs_le16_to_cpu(limit.limit);
fprintf(pager, "Number of entries (count): %d\n", limit.count);
fprintf(pager, "Number of entries (limit): %d\n", limit.limit);
remainder = fs->blocksize - (limit.limit *
sizeof(struct ext2_dx_entry));
if (ent == (struct ext2_dx_entry *)(rootnode + 1))
remainder -= sizeof(struct ext2_dx_root_info) + 24;
else
remainder -= 8;
if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) &&
remainder == sizeof(struct ext2_dx_tail)) {
tail = (struct ext2_dx_tail *)(ent + limit.limit);
fprintf(pager, "Checksum: 0x%08x\n",
ext2fs_le32_to_cpu(tail->dt_checksum));
}
for (i=0; i < limit.count; i++) {
hash = i ? ext2fs_le32_to_cpu(ent[i].hash) : 0;
fprintf(pager, "Entry #%d: Hash 0x%08x%s, block %u\n", i,
hash, (hash & 1) ? " (**)" : "",
ext2fs_le32_to_cpu(ent[i].block));
}
fprintf(pager, "\n");
for (i=0; i < limit.count; i++) {
e.hash = ext2fs_le32_to_cpu(ent[i].hash);
e.block = ext2fs_le32_to_cpu(ent[i].block);
fprintf(pager, "Entry #%d: Hash 0x%08x, block %u\n", i,
i ? e.hash : 0, e.block);
if (level)
htree_dump_int_block(fs, ino, inode, rootnode,
e.block, buf, level-1);
else
htree_dump_leaf_node(fs, ino, inode, rootnode,
e.block, buf);
}
fprintf(pager, "---------------------\n");
}
static void htree_dump_int_block(ext2_filsys fs, ext2_ino_t ino,
struct ext2_inode *inode,
struct ext2_dx_root_info * rootnode,
blk64_t blk, char *buf, int level)
{
char *cbuf;
errcode_t errcode;
blk64_t pblk;
cbuf = malloc(fs->blocksize);
if (!cbuf) {
fprintf(pager, "Couldn't allocate child block.\n");
return;
}
errcode = ext2fs_bmap2(fs, ino, inode, buf, 0, blk, 0, &pblk);
if (errcode) {
com_err("htree_dump_int_block", errcode,
"while mapping logical block %llu\n", blk);
goto errout;
}
errcode = io_channel_read_blk64(current_fs->io, pblk, 1, buf);
if (errcode) {
com_err("htree_dump_int_block", errcode,
"while reading block %llu\n", blk);
goto errout;
}
htree_dump_int_node(fs, ino, inode, rootnode,
(struct ext2_dx_entry *) (buf+8),
cbuf, level);
errout:
free(cbuf);
}
void do_htree_dump(int argc, char *argv[])
{
ext2_ino_t ino;
struct ext2_inode inode;
blk64_t blk;
char *buf = NULL;
struct ext2_dx_root_info *rootnode;
struct ext2_dx_entry *ent;
struct ext2_dx_countlimit *limit;
errcode_t errcode;
if (check_fs_open(argv[0]))
return;
pager = open_pager();
if (common_inode_args_process(argc, argv, &ino, 0))
goto errout;
if (debugfs_read_inode(ino, &inode, argv[1]))
goto errout;
if (!LINUX_S_ISDIR(inode.i_mode)) {
com_err(argv[0], 0, "Not a directory");
goto errout;
}
if ((inode.i_flags & EXT2_BTREE_FL) == 0) {
com_err(argv[0], 0, "Not a hash-indexed directory");
goto errout;
}
buf = malloc(2*current_fs->blocksize);
if (!buf) {
com_err(argv[0], 0, "Couldn't allocate htree buffer");
goto errout;
}
errcode = ext2fs_bmap2(current_fs, ino, &inode, buf, 0, 0, 0, &blk);
if (errcode) {
com_err("do_htree_block", errcode,
"while mapping logical block 0\n");
goto errout;
}
errcode = io_channel_read_blk64(current_fs->io, blk,
1, buf);
if (errcode) {
com_err(argv[0], errcode, "Error reading root node");
goto errout;
}
rootnode = (struct ext2_dx_root_info *) (buf + 24);
fprintf(pager, "Root node dump:\n");
fprintf(pager, "\t Reserved zero: %u\n", rootnode->reserved_zero);
fprintf(pager, "\t Hash Version: %d\n", rootnode->hash_version);
fprintf(pager, "\t Info length: %d\n", rootnode->info_length);
fprintf(pager, "\t Indirect levels: %d\n", rootnode->indirect_levels);
fprintf(pager, "\t Flags: %d\n", rootnode->unused_flags);
ent = (struct ext2_dx_entry *) (buf + 24 + rootnode->info_length);
limit = (struct ext2_dx_countlimit *) ent;
htree_dump_int_node(current_fs, ino, &inode, rootnode, ent,
buf + current_fs->blocksize,
rootnode->indirect_levels);
errout:
free(buf);
close_pager(pager);
}
/*
* This function prints the hash of a given file.
*/
void do_dx_hash(int argc, char *argv[])
{
ext2_dirhash_t hash, minor_hash;
errcode_t err;
int c;
int hash_version = 0;
__u32 hash_seed[4];
hash_seed[0] = hash_seed[1] = hash_seed[2] = hash_seed[3] = 0;
reset_getopt();
while ((c = getopt (argc, argv, "h:s:")) != EOF) {
switch (c) {
case 'h':
hash_version = e2p_string2hash(optarg);
if (hash_version < 0)
hash_version = atoi(optarg);
break;
case 's':
if (uuid_parse(optarg, (unsigned char *) hash_seed)) {
fprintf(stderr, "Invalid UUID format: %s\n",
optarg);
return;
}
break;
default:
goto print_usage;
}
}
if (optind != argc-1) {
print_usage:
com_err(argv[0], 0, "usage: dx_hash [-h hash_alg] "
"[-s hash_seed] filename");
return;
}
err = ext2fs_dirhash(hash_version, argv[optind], strlen(argv[optind]),
hash_seed, &hash, &minor_hash);
if (err) {
com_err(argv[0], err, "while caclulating hash");
return;
}
printf("Hash of %s is 0x%0x (minor 0x%0x)\n", argv[optind],
hash, minor_hash);
}
/*
* Search for particular directory entry (useful for debugging very
* large hash tree directories that have lost some blocks from the
* btree index).
*/
struct process_block_struct {
char *search_name;
char *buf;
int len;
};
static int search_dir_block(ext2_filsys fs, blk64_t *blocknr,
e2_blkcnt_t blockcnt, blk64_t ref_blk,
int ref_offset, void *priv_data);
void do_dirsearch(int argc, char *argv[])
{
ext2_ino_t inode;
struct process_block_struct pb;
if (check_fs_open(argv[0]))
return;
if (argc != 3) {
com_err(0, 0, "Usage: dirsearch dir filename");
return;
}
inode = string_to_inode(argv[1]);
if (!inode)
return;
pb.buf = malloc(current_fs->blocksize);
if (!pb.buf) {
com_err("dirsearch", 0, "Couldn't allocate buffer");
return;
}
pb.search_name = argv[2];
pb.len = strlen(pb.search_name);
ext2fs_block_iterate3(current_fs, inode, BLOCK_FLAG_READ_ONLY, 0,
search_dir_block, &pb);
free(pb.buf);
}
static int search_dir_block(ext2_filsys fs, blk64_t *blocknr,
e2_blkcnt_t blockcnt,
blk64_t ref_blk EXT2FS_ATTR((unused)),
int ref_offset EXT2FS_ATTR((unused)),
void *priv_data)
{
struct process_block_struct *p;
struct ext2_dir_entry *dirent;
errcode_t errcode;
unsigned int offset = 0;
unsigned int rec_len;
if (blockcnt < 0)
return 0;
p = (struct process_block_struct *) priv_data;
errcode = io_channel_read_blk64(current_fs->io, *blocknr, 1, p->buf);
if (errcode) {
com_err("search_dir_block", errcode,
"while reading block %lu", (unsigned long) *blocknr);
return BLOCK_ABORT;
}
while (offset < fs->blocksize) {
dirent = (struct ext2_dir_entry *) (p->buf + offset);
errcode = ext2fs_get_rec_len(fs, dirent, &rec_len);
if (errcode) {
com_err("htree_dump_leaf_inode", errcode,
"while getting rec_len for block %lu",
(unsigned long) *blocknr);
return BLOCK_ABORT;
}
if (dirent->inode &&
p->len == (dirent->name_len & 0xFF) &&
strncmp(p->search_name, dirent->name,
p->len) == 0) {
printf("Entry found at logical block %lld, "
"phys %llu, offset %u\n", (long long)blockcnt,
*blocknr, offset);
printf("offset %u\n", offset);
return BLOCK_ABORT;
}
offset += rec_len;
}
return 0;
}