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samba-mirror/source3/modules/vfs_streams_depot.c

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/*
* Store streams in a separate subdirectory
*
* Copyright (C) Volker Lendecke, 2007
*
* This program 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 3 of the License, or
* (at your option) any later version.
*
* This program 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; if not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#undef DBGC_CLASS
#define DBGC_CLASS DBGC_VFS
/*
* Excerpt from a mail from tridge:
*
* Volker, what I'm thinking of is this:
* /mount-point/.streams/XX/YY/aaaa.bbbb/namedstream1
* /mount-point/.streams/XX/YY/aaaa.bbbb/namedstream2
*
* where XX/YY is a 2 level hash based on the fsid/inode. "aaaa.bbbb"
* is the fsid/inode. "namedstreamX" is a file named after the stream
* name.
*/
static uint32_t hash_fn(DATA_BLOB key)
{
uint32_t value; /* Used to compute the hash value. */
uint32_t i; /* Used to cycle through random values. */
/* Set the initial value from the key size. */
for (value = 0x238F13AF * key.length, i=0; i < key.length; i++)
value = (value + (key.data[i] << (i*5 % 24)));
return (1103515243 * value + 12345);
}
/*
* With the hashing scheme based on the inode we need to protect against
* streams showing up on files with re-used inodes. This can happen if we
* create a stream directory from within Samba, and a local process or NFS
* client deletes the file without deleting the streams directory. When the
* inode is re-used and the stream directory is still around, the streams in
* there would be show up as belonging to the new file.
*
* There are several workarounds for this, probably the easiest one is on
* systems which have a true birthtime stat element: When the file has a later
* birthtime than the streams directory, then we have to recreate the
* directory.
*
* The other workaround is to somehow mark the file as generated by Samba with
* something that a NFS client would not do. The closest one is a special
* xattr value being set. On systems which do not support xattrs, it might be
* an option to put in a special ACL entry for a non-existing group.
*/
#define SAMBA_XATTR_MARKER "user.SAMBA_STREAMS"
static bool file_is_valid(vfs_handle_struct *handle, const char *path,
bool check_valid)
{
char buf;
if (!check_valid) {
return true;
}
DEBUG(10, ("file_is_valid (%s) called\n", path));
if (SMB_VFS_NEXT_GETXATTR(handle, path, SAMBA_XATTR_MARKER,
&buf, sizeof(buf)) != sizeof(buf)) {
DEBUG(10, ("GETXATTR failed: %s\n", strerror(errno)));
return false;
}
if (buf != '1') {
DEBUG(10, ("got wrong buffer content: '%c'\n", buf));
return false;
}
return true;
}
static bool mark_file_valid(vfs_handle_struct *handle, const char *path,
bool check_valid)
{
char buf = '1';
int ret;
if (!check_valid) {
return true;
}
DEBUG(10, ("marking file %s as valid\n", path));
ret = SMB_VFS_NEXT_SETXATTR(handle, path, SAMBA_XATTR_MARKER,
&buf, sizeof(buf), 0);
if (ret == -1) {
DEBUG(10, ("SETXATTR failed: %s\n", strerror(errno)));
return false;
}
return true;
}
static char *stream_dir(vfs_handle_struct *handle, const char *base_path,
const SMB_STRUCT_STAT *base_sbuf, bool create_it)
{
uint32_t hash;
char *result = NULL;
SMB_STRUCT_STAT sbuf;
uint8_t first, second;
char *tmp;
char *id_hex;
struct file_id id;
uint8 id_buf[16];
bool check_valid;
2008-11-22 09:51:20 +03:00
const char *rootdir;
check_valid = lp_parm_bool(SNUM(handle->conn),
"streams_depot", "check_valid", true);
tmp = talloc_asprintf(talloc_tos(), "%s/.streams", handle->conn->connectpath);
if (tmp == NULL) {
errno = ENOMEM;
goto fail;
}
2008-11-22 09:51:20 +03:00
rootdir = lp_parm_const_string(
SNUM(handle->conn), "streams_depot", "directory",
tmp);
if (base_sbuf == NULL) {
if (SMB_VFS_NEXT_STAT(handle, base_path, &sbuf) == -1) {
/*
* base file is not there
*/
goto fail;
}
base_sbuf = &sbuf;
}
id = SMB_VFS_FILE_ID_CREATE(handle->conn, base_sbuf->st_dev,
base_sbuf->st_ino);
push_file_id_16((char *)id_buf, &id);
hash = hash_fn(data_blob_const(id_buf, sizeof(id_buf)));
first = hash & 0xff;
second = (hash >> 8) & 0xff;
2008-11-22 09:51:20 +03:00
id_hex = hex_encode_talloc(talloc_tos(), id_buf, sizeof(id_buf));
if (id_hex == NULL) {
errno = ENOMEM;
goto fail;
}
result = talloc_asprintf(talloc_tos(), "%s/%2.2X/%2.2X/%s", rootdir,
first, second, id_hex);
TALLOC_FREE(id_hex);
if (result == NULL) {
errno = ENOMEM;
return NULL;
}
if (SMB_VFS_NEXT_STAT(handle, result, &sbuf) == 0) {
char *newname;
if (!S_ISDIR(sbuf.st_mode)) {
errno = EINVAL;
goto fail;
}
if (file_is_valid(handle, base_path, check_valid)) {
return result;
}
/*
* Someone has recreated a file under an existing inode
* without deleting the streams directory. For now, just move
* it away.
*/
again:
newname = talloc_asprintf(talloc_tos(), "lost-%lu", random());
if (newname == NULL) {
errno = ENOMEM;
goto fail;
}
if (SMB_VFS_NEXT_RENAME(handle, result, newname) == -1) {
if ((errno == EEXIST) || (errno == ENOTEMPTY)) {
TALLOC_FREE(newname);
goto again;
}
goto fail;
}
TALLOC_FREE(newname);
}
if (!create_it) {
errno = ENOENT;
goto fail;
}
if ((SMB_VFS_NEXT_MKDIR(handle, rootdir, 0755) != 0)
&& (errno != EEXIST)) {
goto fail;
}
tmp = talloc_asprintf(result, "%s/%2.2X", rootdir, first);
if (tmp == NULL) {
errno = ENOMEM;
goto fail;
}
if ((SMB_VFS_NEXT_MKDIR(handle, tmp, 0755) != 0)
&& (errno != EEXIST)) {
goto fail;
}
TALLOC_FREE(tmp);
tmp = talloc_asprintf(result, "%s/%2.2X/%2.2X", rootdir, first,
second);
if (tmp == NULL) {
errno = ENOMEM;
goto fail;
}
if ((SMB_VFS_NEXT_MKDIR(handle, tmp, 0755) != 0)
&& (errno != EEXIST)) {
goto fail;
}
TALLOC_FREE(tmp);
if ((SMB_VFS_NEXT_MKDIR(handle, result, 0755) != 0)
&& (errno != EEXIST)) {
goto fail;
}
if (!mark_file_valid(handle, base_path, check_valid)) {
goto fail;
}
return result;
fail:
TALLOC_FREE(result);
return NULL;
}
static char *stream_name(vfs_handle_struct *handle, const char *fname,
bool create_dir)
{
char *base = NULL;
char *sname = NULL;
char *id_hex = NULL;
char *dirname, *stream_fname;
if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), fname,
&base, &sname))) {
DEBUG(10, ("split_ntfs_stream_name failed\n"));
errno = ENOMEM;
goto fail;
}
/* if it's the ::$DATA stream just return the base file name */
if (!sname) {
return base;
}
dirname = stream_dir(handle, base, NULL, create_dir);
if (dirname == NULL) {
goto fail;
}
stream_fname = talloc_asprintf(talloc_tos(), "%s/:%s", dirname, sname);
if (stream_fname == NULL) {
errno = ENOMEM;
goto fail;
}
DEBUG(10, ("stream filename = %s\n", stream_fname));
TALLOC_FREE(base);
TALLOC_FREE(sname);
TALLOC_FREE(id_hex);
return stream_fname;
fail:
DEBUG(5, ("stream_name failed: %s\n", strerror(errno)));
TALLOC_FREE(base);
TALLOC_FREE(sname);
TALLOC_FREE(id_hex);
return NULL;
}
static NTSTATUS walk_streams(vfs_handle_struct *handle,
const char *fname,
const SMB_STRUCT_STAT *sbuf,
char **pdirname,
bool (*fn)(const char *dirname,
const char *dirent,
void *private_data),
void *private_data)
{
char *dirname;
SMB_STRUCT_DIR *dirhandle = NULL;
char *dirent;
dirname = stream_dir(handle, fname, sbuf, false);
if (dirname == NULL) {
if (errno == ENOENT) {
/*
* no stream around
*/
return NT_STATUS_OK;
}
return map_nt_error_from_unix(errno);
}
DEBUG(10, ("walk_streams: dirname=%s\n", dirname));
dirhandle = SMB_VFS_NEXT_OPENDIR(handle, dirname, NULL, 0);
if (dirhandle == NULL) {
TALLOC_FREE(dirname);
return map_nt_error_from_unix(errno);
}
while ((dirent = vfs_readdirname(handle->conn, dirhandle)) != NULL) {
if (ISDOT(dirent) || ISDOTDOT(dirent)) {
continue;
}
DEBUG(10, ("walk_streams: dirent=%s\n", dirent));
if (!fn(dirname, dirent, private_data)) {
break;
}
}
SMB_VFS_NEXT_CLOSEDIR(handle, dirhandle);
if (pdirname != NULL) {
*pdirname = dirname;
}
else {
TALLOC_FREE(dirname);
}
return NT_STATUS_OK;
}
static int streams_depot_stat(vfs_handle_struct *handle, const char *fname,
SMB_STRUCT_STAT *sbuf)
{
char *stream_fname;
int ret = -1;
DEBUG(10, ("streams_depot_stat called for [%s]\n", fname));
if (!is_ntfs_stream_name(fname)) {
return SMB_VFS_NEXT_STAT(handle, fname, sbuf);
}
stream_fname = stream_name(handle, fname, false);
if (stream_fname == NULL) {
goto done;
}
ret = SMB_VFS_NEXT_STAT(handle, stream_fname, sbuf);
done:
TALLOC_FREE(stream_fname);
return ret;
}
static int streams_depot_lstat(vfs_handle_struct *handle, const char *fname,
SMB_STRUCT_STAT *sbuf)
{
char *stream_fname;
int ret = -1;
if (!is_ntfs_stream_name(fname)) {
return SMB_VFS_NEXT_LSTAT(handle, fname, sbuf);
}
stream_fname = stream_name(handle, fname, false);
if (stream_fname == NULL) {
goto done;
}
ret = SMB_VFS_NEXT_LSTAT(handle, stream_fname, sbuf);
done:
TALLOC_FREE(stream_fname);
return ret;
}
static int streams_depot_open(vfs_handle_struct *handle, const char *fname,
files_struct *fsp, int flags, mode_t mode)
{
TALLOC_CTX *frame;
char *base = NULL;
char *sname = NULL;
SMB_STRUCT_STAT base_sbuf;
char *stream_fname;
int ret = -1;
if (!is_ntfs_stream_name(fname)) {
return SMB_VFS_NEXT_OPEN(handle, fname, fsp, flags, mode);
}
frame = talloc_stackframe();
if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), fname,
&base, &sname))) {
errno = ENOMEM;
goto done;
}
if (!sname) {
ret = SMB_VFS_NEXT_OPEN(handle, base, fsp, flags, mode);
goto done;
}
ret = SMB_VFS_NEXT_STAT(handle, base, &base_sbuf);
if (ret == -1) {
goto done;
}
TALLOC_FREE(base);
stream_fname = stream_name(handle, fname, true);
if (stream_fname == NULL) {
goto done;
}
ret = SMB_VFS_NEXT_OPEN(handle, stream_fname, fsp, flags, mode);
done:
TALLOC_FREE(frame);
return ret;
}
static int streams_depot_unlink(vfs_handle_struct *handle, const char *fname)
{
int ret = -1;
SMB_STRUCT_STAT sbuf;
DEBUG(10, ("streams_depot_unlink called for %s\n", fname));
if (is_ntfs_stream_name(fname)) {
char *stream_fname;
stream_fname = stream_name(handle, fname, false);
if (stream_fname == NULL) {
return -1;
}
ret = SMB_VFS_NEXT_UNLINK(handle, stream_fname);
TALLOC_FREE(stream_fname);
return ret;
}
/*
* We potentially need to delete the per-inode streams directory
*/
if (SMB_VFS_NEXT_STAT(handle, fname, &sbuf) == -1) {
return -1;
}
if (sbuf.st_nlink == 1) {
char *dirname = stream_dir(handle, fname, &sbuf, false);
if (dirname != NULL) {
SMB_VFS_NEXT_RMDIR(handle, dirname);
}
TALLOC_FREE(dirname);
}
return SMB_VFS_NEXT_UNLINK(handle, fname);
}
static int streams_depot_rename(vfs_handle_struct *handle,
const char *oldname,
const char *newname)
{
TALLOC_CTX *frame = NULL;
int ret = -1;
bool old_is_stream;
bool new_is_stream;
char *obase = NULL;
char *osname = NULL;
char *nbase = NULL;
char *nsname = NULL;
char *ostream_fname = NULL;
char *nstream_fname = NULL;
char *newname_full = NULL;
DEBUG(10, ("streams_depot_rename called for %s => %s\n",
oldname, newname));
old_is_stream = is_ntfs_stream_name(oldname);
new_is_stream = is_ntfs_stream_name(newname);
if (!old_is_stream && !new_is_stream) {
return SMB_VFS_NEXT_RENAME(handle, oldname, newname);
}
frame = talloc_stackframe();
if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), oldname,
&obase, &osname))) {
errno = ENOMEM;
goto done;
}
if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), newname,
&nbase, &nsname))) {
errno = ENOMEM;
goto done;
}
/* for now don't allow renames from or to the default stream */
if (!osname || !nsname) {
errno = ENOSYS;
goto done;
}
ostream_fname = stream_name(handle, oldname, false);
if (ostream_fname == NULL) {
return -1;
}
/*
* Handle passing in a stream name without the base file. This is
* exercised by the NTRENAME streams rename path.
*/
if (StrCaseCmp(nbase, "./") == 0) {
newname_full = talloc_asprintf(talloc_tos(), "%s:%s", obase,
nsname);
if (newname_full == NULL) {
errno = ENOMEM;
goto done;
}
}
nstream_fname = stream_name(handle,
newname_full ? newname_full : newname,
false);
if (nstream_fname == NULL) {
return -1;
}
ret = SMB_VFS_NEXT_RENAME(handle, ostream_fname, nstream_fname);
done:
TALLOC_FREE(frame);
return ret;
}
static bool add_one_stream(TALLOC_CTX *mem_ctx, unsigned int *num_streams,
struct stream_struct **streams,
const char *name, SMB_OFF_T size,
SMB_OFF_T alloc_size)
{
struct stream_struct *tmp;
tmp = TALLOC_REALLOC_ARRAY(mem_ctx, *streams, struct stream_struct,
(*num_streams)+1);
if (tmp == NULL) {
return false;
}
tmp[*num_streams].name = talloc_strdup(tmp, name);
if (tmp[*num_streams].name == NULL) {
return false;
}
tmp[*num_streams].size = size;
tmp[*num_streams].alloc_size = alloc_size;
*streams = tmp;
*num_streams += 1;
return true;
}
struct streaminfo_state {
TALLOC_CTX *mem_ctx;
vfs_handle_struct *handle;
unsigned int num_streams;
struct stream_struct *streams;
NTSTATUS status;
};
static bool collect_one_stream(const char *dirname,
const char *dirent,
void *private_data)
{
struct streaminfo_state *state =
(struct streaminfo_state *)private_data;
char *full_sname;
SMB_STRUCT_STAT sbuf;
if (asprintf(&full_sname, "%s/%s", dirname, dirent) == -1) {
state->status = NT_STATUS_NO_MEMORY;
return false;
}
if (SMB_VFS_NEXT_STAT(state->handle, full_sname, &sbuf) == -1) {
DEBUG(10, ("Could not stat %s: %s\n", full_sname,
strerror(errno)));
SAFE_FREE(full_sname);
return true;
}
SAFE_FREE(full_sname);
if (!add_one_stream(state->mem_ctx,
&state->num_streams, &state->streams,
dirent, sbuf.st_size,
SMB_VFS_GET_ALLOC_SIZE(state->handle->conn, NULL,
&sbuf))) {
state->status = NT_STATUS_NO_MEMORY;
return false;
}
return true;
}
static NTSTATUS streams_depot_streaminfo(vfs_handle_struct *handle,
struct files_struct *fsp,
const char *fname,
TALLOC_CTX *mem_ctx,
unsigned int *pnum_streams,
struct stream_struct **pstreams)
{
SMB_STRUCT_STAT sbuf;
int ret;
NTSTATUS status;
struct streaminfo_state state;
if ((fsp != NULL) && (fsp->fh->fd != -1)) {
if (is_ntfs_stream_name(fsp->fsp_name)) {
return NT_STATUS_INVALID_PARAMETER;
}
ret = SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf);
}
else {
if (is_ntfs_stream_name(fname)) {
return NT_STATUS_INVALID_PARAMETER;
}
ret = SMB_VFS_NEXT_STAT(handle, fname, &sbuf);
}
if (ret == -1) {
return map_nt_error_from_unix(errno);
}
state.streams = NULL;
state.num_streams = 0;
if (!S_ISDIR(sbuf.st_mode)) {
if (!add_one_stream(mem_ctx,
&state.num_streams, &state.streams,
"::$DATA", sbuf.st_size,
SMB_VFS_GET_ALLOC_SIZE(handle->conn, fsp,
&sbuf))) {
return NT_STATUS_NO_MEMORY;
}
}
state.mem_ctx = mem_ctx;
state.handle = handle;
state.status = NT_STATUS_OK;
status = walk_streams(handle, fname, &sbuf, NULL, collect_one_stream,
&state);
if (!NT_STATUS_IS_OK(status)) {
TALLOC_FREE(state.streams);
return status;
}
if (!NT_STATUS_IS_OK(state.status)) {
TALLOC_FREE(state.streams);
return state.status;
}
*pnum_streams = state.num_streams;
*pstreams = state.streams;
return NT_STATUS_OK;
}
static uint32_t streams_depot_fs_capabilities(struct vfs_handle_struct *handle)
{
return SMB_VFS_NEXT_FS_CAPABILITIES(handle) | FILE_NAMED_STREAMS;
}
/* VFS operations structure */
static vfs_op_tuple streams_depot_ops[] = {
{SMB_VFS_OP(streams_depot_fs_capabilities), SMB_VFS_OP_FS_CAPABILITIES,
SMB_VFS_LAYER_TRANSPARENT},
{SMB_VFS_OP(streams_depot_open), SMB_VFS_OP_OPEN,
SMB_VFS_LAYER_TRANSPARENT},
{SMB_VFS_OP(streams_depot_stat), SMB_VFS_OP_STAT,
SMB_VFS_LAYER_TRANSPARENT},
{SMB_VFS_OP(streams_depot_lstat), SMB_VFS_OP_LSTAT,
SMB_VFS_LAYER_TRANSPARENT},
{SMB_VFS_OP(streams_depot_unlink), SMB_VFS_OP_UNLINK,
SMB_VFS_LAYER_TRANSPARENT},
{SMB_VFS_OP(streams_depot_rename), SMB_VFS_OP_RENAME,
SMB_VFS_LAYER_TRANSPARENT},
{SMB_VFS_OP(streams_depot_streaminfo), SMB_VFS_OP_STREAMINFO,
SMB_VFS_LAYER_OPAQUE},
{SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP}
};
NTSTATUS vfs_streams_depot_init(void);
NTSTATUS vfs_streams_depot_init(void)
{
return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "streams_depot",
streams_depot_ops);
}