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ntfs-3g/libntfs-3g/object_id.c

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/**
* object_id.c - Processing of object ids
*
* This module is part of ntfs-3g library
*
* Copyright (c) 2009 Jean-Pierre Andre
*
* This program/include file is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program/include file is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (in the main directory of the NTFS-3G
* distribution in the file COPYING); if not, write to the Free Software
* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_SETXATTR
#include <sys/xattr.h>
#endif
#ifdef HAVE_SYS_SYSMACROS_H
#include <sys/sysmacros.h>
#endif
#include "types.h"
#include "debug.h"
#include "attrib.h"
#include "inode.h"
#include "dir.h"
#include "volume.h"
#include "mft.h"
#include "index.h"
#include "lcnalloc.h"
#include "object_id.h"
#include "logging.h"
#include "misc.h"
/*
* Endianness considerations
*
* According to RFC 4122, GUIDs should be printed with the most
* significant byte first, and the six fields be compared individually
* for ordering. RFC 4122 does not define the internal representation.
*
* Here we always copy disk images with no endianness change,
* and, for indexing, GUIDs are compared as if they were a sequence
* of four unsigned 32 bit integers.
*
* --------------------- begin from RFC 4122 ----------------------
* Consider each field of the UUID to be an unsigned integer as shown
* in the table in section Section 4.1.2. Then, to compare a pair of
* UUIDs, arithmetically compare the corresponding fields from each
* UUID in order of significance and according to their data type.
* Two UUIDs are equal if and only if all the corresponding fields
* are equal.
*
* UUIDs, as defined in this document, can also be ordered
* lexicographically. For a pair of UUIDs, the first one follows the
* second if the most significant field in which the UUIDs differ is
* greater for the first UUID. The second precedes the first if the
* most significant field in which the UUIDs differ is greater for
* the second UUID.
*
* The fields are encoded as 16 octets, with the sizes and order of the
* fields defined above, and with each field encoded with the Most
* Significant Byte first (known as network byte order). Note that the
* field names, particularly for multiplexed fields, follow historical
* practice.
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | time_low |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | time_mid | time_hi_and_version |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |clk_seq_hi_res | clk_seq_low | node (0-1) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | node (2-5) |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* ---------------------- end from RFC 4122 -----------------------
*/
typedef struct {
GUID object_id;
} OBJECT_ID_INDEX_KEY;
typedef struct {
le64 file_id;
GUID birth_volume_id;
GUID birth_object_id;
GUID domain_id;
} OBJECT_ID_INDEX_DATA; // known as OBJ_ID_INDEX_DATA
struct OBJECT_ID_INDEX { /* index entry in $Extend/$ObjId */
INDEX_ENTRY_HEADER header;
OBJECT_ID_INDEX_KEY key;
OBJECT_ID_INDEX_DATA data;
} ;
static ntfschar objid_index_name[] = { const_cpu_to_le16('$'),
const_cpu_to_le16('O') };
#ifdef HAVE_SETXATTR /* extended attributes interface required */
/*
* Set the index for a new object id
*
* Returns 0 if success
* -1 if failure, explained by errno
*/
static int set_object_id_index(ntfs_inode *ni, ntfs_index_context *xo,
const OBJECT_ID_ATTR *object_id)
{
struct OBJECT_ID_INDEX indx;
u64 file_id_cpu;
le64 file_id;
le16 seqn;
seqn = ni->mrec->sequence_number;
file_id_cpu = MK_MREF(ni->mft_no,le16_to_cpu(seqn));
file_id = cpu_to_le64(file_id_cpu);
indx.header.data_offset = const_cpu_to_le16(
sizeof(INDEX_ENTRY_HEADER)
+ sizeof(OBJECT_ID_INDEX_KEY));
indx.header.data_length = const_cpu_to_le16(
sizeof(OBJECT_ID_INDEX_DATA));
indx.header.reservedV = const_cpu_to_le32(0);
indx.header.length = const_cpu_to_le16(
sizeof(struct OBJECT_ID_INDEX));
indx.header.key_length = const_cpu_to_le16(
sizeof(OBJECT_ID_INDEX_KEY));
indx.header.flags = const_cpu_to_le16(0);
indx.header.reserved = const_cpu_to_le16(0);
memcpy(&indx.key.object_id,object_id,sizeof(GUID));
indx.data.file_id = file_id;
memcpy(&indx.data.birth_volume_id,
&object_id->birth_volume_id,sizeof(GUID));
memcpy(&indx.data.birth_object_id,
&object_id->birth_object_id,sizeof(GUID));
memcpy(&indx.data.domain_id,
&object_id->domain_id,sizeof(GUID));
ntfs_index_ctx_reinit(xo);
return (ntfs_ie_add(xo,(INDEX_ENTRY*)&indx));
}
#endif /* HAVE_SETXATTR */
/*
* Open the $Extend/$ObjId file and its index
*
* Return the index context if opened
* or NULL if an error occurred (errno tells why)
*
* The index has to be freed and inode closed when not needed any more.
*/
static ntfs_index_context *open_object_id_index(ntfs_volume *vol)
{
u64 inum;
ntfs_inode *ni;
ntfs_inode *dir_ni;
ntfs_index_context *xo;
/* do not use path_name_to inode - could reopen root */
dir_ni = ntfs_inode_open(vol, FILE_Extend);
ni = (ntfs_inode*)NULL;
if (dir_ni) {
inum = ntfs_inode_lookup_by_mbsname(dir_ni,"$ObjId");
if (inum != (u64)-1)
ni = ntfs_inode_open(vol, inum);
ntfs_inode_close(dir_ni);
}
if (ni) {
xo = ntfs_index_ctx_get(ni, objid_index_name, 2);
if (!xo) {
ntfs_inode_close(ni);
}
} else
xo = (ntfs_index_context*)NULL;
return (xo);
}
#ifdef HAVE_SETXATTR /* extended attributes interface required */
/*
* Merge object_id data stored in the index into
* a full object_id struct.
*
* returns 0 if merging successful
* -1 if no data could be merged. This is generally not an error
*/
static int merge_index_data(ntfs_inode *ni,
const OBJECT_ID_ATTR *objectid_attr,
OBJECT_ID_ATTR *full_objectid)
{
OBJECT_ID_INDEX_KEY key;
struct OBJECT_ID_INDEX *entry;
ntfs_index_context *xo;
ntfs_inode *xoni;
int res;
res = -1;
xo = open_object_id_index(ni->vol);
if (xo) {
memcpy(&key.object_id,objectid_attr,sizeof(GUID));
if (!ntfs_index_lookup(&key,
sizeof(OBJECT_ID_INDEX_KEY), xo)) {
entry = (struct OBJECT_ID_INDEX*)xo->entry;
/* make sure inode numbers match */
if (entry
&& (MREF(le64_to_cpu(entry->data.file_id))
== ni->mft_no)) {
memcpy(&full_objectid->birth_volume_id,
&entry->data.birth_volume_id,
sizeof(GUID));
memcpy(&full_objectid->birth_object_id,
&entry->data.birth_object_id,
sizeof(GUID));
memcpy(&full_objectid->domain_id,
&entry->data.domain_id,
sizeof(GUID));
res = 0;
}
}
xoni = xo->ni;
ntfs_index_ctx_put(xo);
ntfs_inode_close(xoni);
}
return (res);
}
#endif /* HAVE_SETXATTR */
/*
* Remove an object id index entry if attribute present
*
* Returns the size of existing object id
* (the existing object_d is returned)
* -1 if failure, explained by errno
*/
static int remove_object_id_index(ntfs_attr *na, ntfs_index_context *xo,
OBJECT_ID_ATTR *old_attr)
{
OBJECT_ID_INDEX_KEY key;
struct OBJECT_ID_INDEX *entry;
s64 size;
int ret;
ret = na->data_size;
if (ret) {
/* read the existing object id attribute */
size = ntfs_attr_pread(na, 0, sizeof(GUID), old_attr);
if (size >= (s64)sizeof(GUID)) {
memcpy(&key.object_id,
&old_attr->object_id,sizeof(GUID));
size = sizeof(GUID);
if (!ntfs_index_lookup(&key,
sizeof(OBJECT_ID_INDEX_KEY), xo)) {
entry = (struct OBJECT_ID_INDEX*)xo->entry;
memcpy(&old_attr->birth_volume_id,
&entry->data.birth_volume_id,
sizeof(GUID));
memcpy(&old_attr->birth_object_id,
&entry->data.birth_object_id,
sizeof(GUID));
memcpy(&old_attr->domain_id,
&entry->data.domain_id,
sizeof(GUID));
size = sizeof(OBJECT_ID_ATTR);
if (ntfs_index_rm(xo))
ret = -1;
}
} else {
ret = -1;
errno = ENODATA;
}
}
return (ret);
}
#ifdef HAVE_SETXATTR /* extended attributes interface required */
/*
* Update the object id and index
*
* The object_id attribute should have been created and the
* non-duplication of the GUID should have been checked before.
*
* Returns 0 if success
* -1 if failure, explained by errno
* If could not remove the existing index, nothing is done,
* If could not write the new data, no index entry is inserted
* If failed to insert the index, data is removed
*/
static int update_object_id(ntfs_inode *ni, ntfs_index_context *xo,
const OBJECT_ID_ATTR *value, size_t size)
{
OBJECT_ID_ATTR old_attr;
ntfs_attr *na;
int oldsize;
int written;
int res;
res = 0;
na = ntfs_attr_open(ni, AT_OBJECT_ID, AT_UNNAMED, 0);
if (na) {
/* remove the existing index entry */
oldsize = remove_object_id_index(na,xo,&old_attr);
if (oldsize < 0)
res = -1;
else {
/* resize attribute */
res = ntfs_attr_truncate(na, (s64)sizeof(GUID));
/* write the object_id in attribute */
if (!res && value) {
written = (int)ntfs_attr_pwrite(na,
(s64)0, (s64)sizeof(GUID),
&value->object_id);
if (written != (s64)sizeof(GUID)) {
ntfs_log_error("Failed to update "
"object id\n");
errno = EIO;
res = -1;
}
}
/* write index part if provided */
if (!res
&& ((size < sizeof(OBJECT_ID_ATTR))
|| set_object_id_index(ni,xo,value))) {
/*
* If cannot index, try to remove the object
* id and log the error. There will be an
* inconsistency if removal fails.
*/
ntfs_attr_rm(na);
ntfs_log_error("Failed to index object id."
" Possible corruption.\n");
}
}
ntfs_attr_close(na);
NInoSetDirty(ni);
} else
res = -1;
return (res);
}
/*
* Add a (dummy) object id to an inode if it does not exist
*
* returns 0 if attribute was inserted (or already present)
* -1 if adding failed (explained by errno)
*/
static int add_object_id(ntfs_inode *ni, int flags)
{
int res;
u8 dummy;
res = -1; /* default return */
if (!ntfs_attr_exist(ni,AT_OBJECT_ID, AT_UNNAMED,0)) {
if (!(flags & XATTR_REPLACE)) {
/*
* no object id attribute : add one,
* apparently, this does not feed the new value in
* Note : NTFS version must be >= 3
*/
if (ni->vol->major_ver >= 3) {
res = ntfs_attr_add(ni, AT_OBJECT_ID,
AT_UNNAMED, 0, &dummy, (s64)0);
NInoSetDirty(ni);
} else
errno = EOPNOTSUPP;
} else
errno = ENODATA;
} else {
if (flags & XATTR_CREATE)
errno = EEXIST;
else
res = 0;
}
return (res);
}
#endif /* HAVE_SETXATTR */
/*
* Delete an object_id index entry
*
* Returns 0 if success
* -1 if failure, explained by errno
*/
int ntfs_delete_object_id_index(ntfs_inode *ni)
{
ntfs_index_context *xo;
ntfs_inode *xoni;
ntfs_attr *na;
OBJECT_ID_ATTR old_attr;
int res;
res = 0;
na = ntfs_attr_open(ni, AT_OBJECT_ID, AT_UNNAMED, 0);
if (na) {
/*
* read the existing object id
* and un-index it
*/
xo = open_object_id_index(ni->vol);
if (xo) {
if (remove_object_id_index(na,xo,&old_attr) < 0)
res = -1;
xoni = xo->ni;
ntfs_index_entry_mark_dirty(xo);
NInoSetDirty(xoni);
ntfs_index_ctx_put(xo);
ntfs_inode_close(xoni);
}
ntfs_attr_close(na);
}
return (res);
}
#ifdef HAVE_SETXATTR /* extended attributes interface required */
/*
* Get the ntfs object id into an extended attribute
*
* If present, the object_id from the attribute and the GUIDs
* from the index are returned (formatted as OBJECT_ID_ATTR)
*
* Returns the global size (can be 0, 16 or 64)
* and the buffer is updated if it is long enough
*/
int ntfs_get_ntfs_object_id(ntfs_inode *ni, char *value, size_t size)
{
OBJECT_ID_ATTR full_objectid;
OBJECT_ID_ATTR *objectid_attr;
s64 attr_size;
int full_size;
full_size = 0; /* default to no data and some error to be defined */
if (ni) {
objectid_attr = (OBJECT_ID_ATTR*)ntfs_attr_readall(ni,
AT_OBJECT_ID,(ntfschar*)NULL, 0, &attr_size);
if (objectid_attr) {
/* restrict to only GUID present in attr */
if (attr_size == sizeof(GUID)) {
memcpy(&full_objectid.object_id,
objectid_attr,sizeof(GUID));
full_size = sizeof(GUID);
/* get data from index, if any */
if (!merge_index_data(ni, objectid_attr,
&full_objectid)) {
full_size = sizeof(OBJECT_ID_ATTR);
}
if (full_size <= (s64)size) {
if (value)
memcpy(value,&full_objectid,
full_size);
else
errno = EINVAL;
}
} else {
/* unexpected size, better return unsupported */
errno = EOPNOTSUPP;
full_size = 0;
}
free(objectid_attr);
} else
errno = ENODATA;
}
return (full_size ? (int)full_size : -errno);
}
/*
* Set the object id from an extended attribute
*
* If the size is 64, the attribute and index are set.
* else if the size is not less than 16 only the attribute is set.
* The object id index is set accordingly.
*
* Returns 0, or -1 if there is a problem
*/
int ntfs_set_ntfs_object_id(ntfs_inode *ni,
const char *value, size_t size, int flags)
{
OBJECT_ID_INDEX_KEY key;
ntfs_inode *xoni;
ntfs_index_context *xo;
int res;
res = 0;
if (ni && value && (size >= sizeof(GUID))) {
xo = open_object_id_index(ni->vol);
if (xo) {
/* make sure the GUID was not used somewhere */
memcpy(&key.object_id, value, sizeof(GUID));
if (ntfs_index_lookup(&key,
sizeof(OBJECT_ID_INDEX_KEY), xo)) {
ntfs_index_ctx_reinit(xo);
res = add_object_id(ni, flags);
if (!res) {
/* update value and index */
res = update_object_id(ni,xo,
(const OBJECT_ID_ATTR*)value,
size);
}
} else {
/* GUID is present elsewhere */
res = -1;
errno = EEXIST;
}
xoni = xo->ni;
ntfs_index_entry_mark_dirty(xo);
NInoSetDirty(xoni);
ntfs_index_ctx_put(xo);
ntfs_inode_close(xoni);
} else {
res = -1;
}
} else {
errno = EINVAL;
res = -1;
}
return (res ? -1 : 0);
}
/*
* Remove the object id
*
* Returns 0, or -1 if there is a problem
*/
int ntfs_remove_ntfs_object_id(ntfs_inode *ni)
{
int res;
int olderrno;
ntfs_attr *na;
ntfs_inode *xoni;
ntfs_index_context *xo;
int oldsize;
OBJECT_ID_ATTR old_attr;
res = 0;
if (ni) {
/*
* open and delete the object id
*/
na = ntfs_attr_open(ni, AT_OBJECT_ID,
AT_UNNAMED,0);
if (na) {
/* first remove index (old object id needed) */
xo = open_object_id_index(ni->vol);
if (xo) {
oldsize = remove_object_id_index(na,xo,
&old_attr);
if (oldsize < 0) {
res = -1;
} else {
/* now remove attribute */
res = ntfs_attr_rm(na);
if (res
&& (oldsize > (int)sizeof(GUID))) {
/*
* If we could not remove the
* attribute, try to restore the
* index and log the error. There
* will be an inconsistency if
* the reindexing fails.
*/
set_object_id_index(ni, xo,
&old_attr);
ntfs_log_error(
"Failed to remove object id."
" Possible corruption.\n");
}
}
xoni = xo->ni;
ntfs_index_entry_mark_dirty(xo);
NInoSetDirty(xoni);
ntfs_index_ctx_put(xo);
ntfs_inode_close(xoni);
}
olderrno = errno;
ntfs_attr_close(na);
/* avoid errno pollution */
if (errno == ENOENT)
errno = olderrno;
} else {
errno = ENODATA;
res = -1;
}
NInoSetDirty(ni);
} else {
errno = EINVAL;
res = -1;
}
return (res ? -1 : 0);
}
#endif /* HAVE_SETXATTR */
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