2 * Store streams in a separate subdirectory
4 * Copyright (C) Volker Lendecke, 2007
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
23 #define DBGC_CLASS DBGC_VFS
26 * Excerpt from a mail from tridge:
28 * Volker, what I'm thinking of is this:
29 * /mount-point/.streams/XX/YY/aaaa.bbbb/namedstream1
30 * /mount-point/.streams/XX/YY/aaaa.bbbb/namedstream2
32 * where XX/YY is a 2 level hash based on the fsid/inode. "aaaa.bbbb"
33 * is the fsid/inode. "namedstreamX" is a file named after the stream
37 static uint32_t hash_fn(DATA_BLOB key)
39 uint32_t value; /* Used to compute the hash value. */
40 uint32_t i; /* Used to cycle through random values. */
42 /* Set the initial value from the key size. */
43 for (value = 0x238F13AF * key.length, i=0; i < key.length; i++)
44 value = (value + (key.data[i] << (i*5 % 24)));
46 return (1103515243 * value + 12345);
50 * With the hashing scheme based on the inode we need to protect against
51 * streams showing up on files with re-used inodes. This can happen if we
52 * create a stream directory from within Samba, and a local process or NFS
53 * client deletes the file without deleting the streams directory. When the
54 * inode is re-used and the stream directory is still around, the streams in
55 * there would be show up as belonging to the new file.
57 * There are several workarounds for this, probably the easiest one is on
58 * systems which have a true birthtime stat element: When the file has a later
59 * birthtime than the streams directory, then we have to recreate the
62 * The other workaround is to somehow mark the file as generated by Samba with
63 * something that a NFS client would not do. The closest one is a special
64 * xattr value being set. On systems which do not support xattrs, it might be
65 * an option to put in a special ACL entry for a non-existing group.
68 #define SAMBA_XATTR_MARKER "user.SAMBA_STREAMS"
70 static bool file_is_valid(vfs_handle_struct *handle, const char *path,
79 DEBUG(10, ("file_is_valid (%s) called\n", path));
81 if (SMB_VFS_NEXT_GETXATTR(handle, path, SAMBA_XATTR_MARKER,
82 &buf, sizeof(buf)) != sizeof(buf)) {
83 DEBUG(10, ("GETXATTR failed: %s\n", strerror(errno)));
88 DEBUG(10, ("got wrong buffer content: '%c'\n", buf));
95 static bool mark_file_valid(vfs_handle_struct *handle, const char *path,
105 DEBUG(10, ("marking file %s as valid\n", path));
107 ret = SMB_VFS_NEXT_SETXATTR(handle, path, SAMBA_XATTR_MARKER,
108 &buf, sizeof(buf), 0);
111 DEBUG(10, ("SETXATTR failed: %s\n", strerror(errno)));
118 static char *stream_dir(vfs_handle_struct *handle, const char *base_path,
119 const SMB_STRUCT_STAT *base_sbuf, bool create_it)
123 SMB_STRUCT_STAT sbuf;
124 uint8_t first, second;
132 check_valid = lp_parm_bool(SNUM(handle->conn),
133 "streams_depot", "check_valid", true);
135 tmp = talloc_asprintf(talloc_tos(), "%s/.streams", handle->conn->connectpath);
142 rootdir = lp_parm_const_string(
143 SNUM(handle->conn), "streams_depot", "directory",
146 if (base_sbuf == NULL) {
147 if (SMB_VFS_NEXT_STAT(handle, base_path, &sbuf) == -1) {
149 * base file is not there
156 id = SMB_VFS_FILE_ID_CREATE(handle->conn, base_sbuf->st_dev,
159 push_file_id_16((char *)id_buf, &id);
161 hash = hash_fn(data_blob_const(id_buf, sizeof(id_buf)));
164 second = (hash >> 8) & 0xff;
166 id_hex = hex_encode_talloc(talloc_tos(), id_buf, sizeof(id_buf));
168 if (id_hex == NULL) {
173 result = talloc_asprintf(talloc_tos(), "%s/%2.2X/%2.2X/%s", rootdir,
174 first, second, id_hex);
178 if (result == NULL) {
183 if (SMB_VFS_NEXT_STAT(handle, result, &sbuf) == 0) {
186 if (!S_ISDIR(sbuf.st_mode)) {
191 if (file_is_valid(handle, base_path, check_valid)) {
196 * Someone has recreated a file under an existing inode
197 * without deleting the streams directory. For now, just move
202 newname = talloc_asprintf(talloc_tos(), "lost-%lu", random());
203 if (newname == NULL) {
208 if (SMB_VFS_NEXT_RENAME(handle, result, newname) == -1) {
209 if ((errno == EEXIST) || (errno == ENOTEMPTY)) {
210 TALLOC_FREE(newname);
216 TALLOC_FREE(newname);
224 if ((SMB_VFS_NEXT_MKDIR(handle, rootdir, 0755) != 0)
225 && (errno != EEXIST)) {
229 tmp = talloc_asprintf(result, "%s/%2.2X", rootdir, first);
235 if ((SMB_VFS_NEXT_MKDIR(handle, tmp, 0755) != 0)
236 && (errno != EEXIST)) {
242 tmp = talloc_asprintf(result, "%s/%2.2X/%2.2X", rootdir, first,
249 if ((SMB_VFS_NEXT_MKDIR(handle, tmp, 0755) != 0)
250 && (errno != EEXIST)) {
256 if ((SMB_VFS_NEXT_MKDIR(handle, result, 0755) != 0)
257 && (errno != EEXIST)) {
261 if (!mark_file_valid(handle, base_path, check_valid)) {
272 static char *stream_name(vfs_handle_struct *handle, const char *fname,
278 char *dirname, *stream_fname;
280 if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), fname,
282 DEBUG(10, ("split_ntfs_stream_name failed\n"));
287 /* if it's the ::$DATA stream just return the base file name */
292 dirname = stream_dir(handle, base, NULL, create_dir);
294 if (dirname == NULL) {
298 stream_fname = talloc_asprintf(talloc_tos(), "%s/:%s", dirname, sname);
300 if (stream_fname == NULL) {
305 DEBUG(10, ("stream filename = %s\n", stream_fname));
314 DEBUG(5, ("stream_name failed: %s\n", strerror(errno)));
321 static NTSTATUS walk_streams(vfs_handle_struct *handle,
323 const SMB_STRUCT_STAT *sbuf,
325 bool (*fn)(const char *dirname,
331 SMB_STRUCT_DIR *dirhandle = NULL;
334 dirname = stream_dir(handle, fname, sbuf, false);
336 if (dirname == NULL) {
337 if (errno == ENOENT) {
343 return map_nt_error_from_unix(errno);
346 DEBUG(10, ("walk_streams: dirname=%s\n", dirname));
348 dirhandle = SMB_VFS_NEXT_OPENDIR(handle, dirname, NULL, 0);
350 if (dirhandle == NULL) {
351 TALLOC_FREE(dirname);
352 return map_nt_error_from_unix(errno);
355 while ((dirent = vfs_readdirname(handle->conn, dirhandle)) != NULL) {
357 if (ISDOT(dirent) || ISDOTDOT(dirent)) {
361 DEBUG(10, ("walk_streams: dirent=%s\n", dirent));
363 if (!fn(dirname, dirent, private_data)) {
368 SMB_VFS_NEXT_CLOSEDIR(handle, dirhandle);
370 if (pdirname != NULL) {
374 TALLOC_FREE(dirname);
380 static int streams_depot_stat(vfs_handle_struct *handle, const char *fname,
381 SMB_STRUCT_STAT *sbuf)
386 DEBUG(10, ("streams_depot_stat called for [%s]\n", fname));
388 if (!is_ntfs_stream_name(fname)) {
389 return SMB_VFS_NEXT_STAT(handle, fname, sbuf);
392 stream_fname = stream_name(handle, fname, false);
393 if (stream_fname == NULL) {
397 ret = SMB_VFS_NEXT_STAT(handle, stream_fname, sbuf);
400 TALLOC_FREE(stream_fname);
404 static int streams_depot_lstat(vfs_handle_struct *handle, const char *fname,
405 SMB_STRUCT_STAT *sbuf)
410 if (!is_ntfs_stream_name(fname)) {
411 return SMB_VFS_NEXT_LSTAT(handle, fname, sbuf);
414 stream_fname = stream_name(handle, fname, false);
415 if (stream_fname == NULL) {
419 ret = SMB_VFS_NEXT_LSTAT(handle, stream_fname, sbuf);
422 TALLOC_FREE(stream_fname);
426 static int streams_depot_open(vfs_handle_struct *handle, const char *fname,
427 files_struct *fsp, int flags, mode_t mode)
432 SMB_STRUCT_STAT base_sbuf;
436 if (!is_ntfs_stream_name(fname)) {
437 return SMB_VFS_NEXT_OPEN(handle, fname, fsp, flags, mode);
440 frame = talloc_stackframe();
442 if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), fname,
449 ret = SMB_VFS_NEXT_OPEN(handle, base, fsp, flags, mode);
453 ret = SMB_VFS_NEXT_STAT(handle, base, &base_sbuf);
461 stream_fname = stream_name(handle, fname, true);
462 if (stream_fname == NULL) {
466 ret = SMB_VFS_NEXT_OPEN(handle, stream_fname, fsp, flags, mode);
473 static int streams_depot_unlink(vfs_handle_struct *handle, const char *fname)
476 SMB_STRUCT_STAT sbuf;
478 DEBUG(10, ("streams_depot_unlink called for %s\n", fname));
480 if (is_ntfs_stream_name(fname)) {
483 stream_fname = stream_name(handle, fname, false);
484 if (stream_fname == NULL) {
488 ret = SMB_VFS_NEXT_UNLINK(handle, stream_fname);
490 TALLOC_FREE(stream_fname);
495 * We potentially need to delete the per-inode streams directory
498 if (SMB_VFS_NEXT_STAT(handle, fname, &sbuf) == -1) {
502 if (sbuf.st_nlink == 1) {
503 char *dirname = stream_dir(handle, fname, &sbuf, false);
505 if (dirname != NULL) {
506 SMB_VFS_NEXT_RMDIR(handle, dirname);
508 TALLOC_FREE(dirname);
511 return SMB_VFS_NEXT_UNLINK(handle, fname);
514 static int streams_depot_rename(vfs_handle_struct *handle,
518 TALLOC_CTX *frame = NULL;
526 char *ostream_fname = NULL;
527 char *nstream_fname = NULL;
528 char *newname_full = NULL;
530 DEBUG(10, ("streams_depot_rename called for %s => %s\n",
533 old_is_stream = is_ntfs_stream_name(oldname);
534 new_is_stream = is_ntfs_stream_name(newname);
536 if (!old_is_stream && !new_is_stream) {
537 return SMB_VFS_NEXT_RENAME(handle, oldname, newname);
540 frame = talloc_stackframe();
542 if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), oldname,
548 if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), newname,
554 /* for now don't allow renames from or to the default stream */
555 if (!osname || !nsname) {
560 ostream_fname = stream_name(handle, oldname, false);
561 if (ostream_fname == NULL) {
566 * Handle passing in a stream name without the base file. This is
567 * exercised by the NTRENAME streams rename path.
569 if (StrCaseCmp(nbase, "./") == 0) {
570 newname_full = talloc_asprintf(talloc_tos(), "%s:%s", obase,
572 if (newname_full == NULL) {
578 nstream_fname = stream_name(handle,
579 newname_full ? newname_full : newname,
581 if (nstream_fname == NULL) {
585 ret = SMB_VFS_NEXT_RENAME(handle, ostream_fname, nstream_fname);
592 static bool add_one_stream(TALLOC_CTX *mem_ctx, unsigned int *num_streams,
593 struct stream_struct **streams,
594 const char *name, SMB_OFF_T size,
595 SMB_OFF_T alloc_size)
597 struct stream_struct *tmp;
599 tmp = TALLOC_REALLOC_ARRAY(mem_ctx, *streams, struct stream_struct,
605 tmp[*num_streams].name = talloc_strdup(tmp, name);
606 if (tmp[*num_streams].name == NULL) {
610 tmp[*num_streams].size = size;
611 tmp[*num_streams].alloc_size = alloc_size;
618 struct streaminfo_state {
620 vfs_handle_struct *handle;
621 unsigned int num_streams;
622 struct stream_struct *streams;
626 static bool collect_one_stream(const char *dirname,
630 struct streaminfo_state *state =
631 (struct streaminfo_state *)private_data;
633 SMB_STRUCT_STAT sbuf;
635 if (asprintf(&full_sname, "%s/%s", dirname, dirent) == -1) {
636 state->status = NT_STATUS_NO_MEMORY;
639 if (SMB_VFS_NEXT_STAT(state->handle, full_sname, &sbuf) == -1) {
640 DEBUG(10, ("Could not stat %s: %s\n", full_sname,
642 SAFE_FREE(full_sname);
646 SAFE_FREE(full_sname);
648 if (!add_one_stream(state->mem_ctx,
649 &state->num_streams, &state->streams,
650 dirent, sbuf.st_size,
651 SMB_VFS_GET_ALLOC_SIZE(state->handle->conn, NULL,
653 state->status = NT_STATUS_NO_MEMORY;
660 static NTSTATUS streams_depot_streaminfo(vfs_handle_struct *handle,
661 struct files_struct *fsp,
664 unsigned int *pnum_streams,
665 struct stream_struct **pstreams)
667 SMB_STRUCT_STAT sbuf;
670 struct streaminfo_state state;
672 if ((fsp != NULL) && (fsp->fh->fd != -1)) {
673 if (is_ntfs_stream_name(fsp->fsp_name)) {
674 return NT_STATUS_INVALID_PARAMETER;
676 ret = SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf);
679 if (is_ntfs_stream_name(fname)) {
680 return NT_STATUS_INVALID_PARAMETER;
682 ret = SMB_VFS_NEXT_STAT(handle, fname, &sbuf);
686 return map_nt_error_from_unix(errno);
689 state.streams = NULL;
690 state.num_streams = 0;
692 if (!S_ISDIR(sbuf.st_mode)) {
693 if (!add_one_stream(mem_ctx,
694 &state.num_streams, &state.streams,
695 "::$DATA", sbuf.st_size,
696 SMB_VFS_GET_ALLOC_SIZE(handle->conn, fsp,
698 return NT_STATUS_NO_MEMORY;
702 state.mem_ctx = mem_ctx;
703 state.handle = handle;
704 state.status = NT_STATUS_OK;
706 status = walk_streams(handle, fname, &sbuf, NULL, collect_one_stream,
709 if (!NT_STATUS_IS_OK(status)) {
710 TALLOC_FREE(state.streams);
714 if (!NT_STATUS_IS_OK(state.status)) {
715 TALLOC_FREE(state.streams);
719 *pnum_streams = state.num_streams;
720 *pstreams = state.streams;
724 static uint32_t streams_depot_fs_capabilities(struct vfs_handle_struct *handle)
726 return SMB_VFS_NEXT_FS_CAPABILITIES(handle) | FILE_NAMED_STREAMS;
729 /* VFS operations structure */
731 static vfs_op_tuple streams_depot_ops[] = {
732 {SMB_VFS_OP(streams_depot_fs_capabilities), SMB_VFS_OP_FS_CAPABILITIES,
733 SMB_VFS_LAYER_TRANSPARENT},
734 {SMB_VFS_OP(streams_depot_open), SMB_VFS_OP_OPEN,
735 SMB_VFS_LAYER_TRANSPARENT},
736 {SMB_VFS_OP(streams_depot_stat), SMB_VFS_OP_STAT,
737 SMB_VFS_LAYER_TRANSPARENT},
738 {SMB_VFS_OP(streams_depot_lstat), SMB_VFS_OP_LSTAT,
739 SMB_VFS_LAYER_TRANSPARENT},
740 {SMB_VFS_OP(streams_depot_unlink), SMB_VFS_OP_UNLINK,
741 SMB_VFS_LAYER_TRANSPARENT},
742 {SMB_VFS_OP(streams_depot_rename), SMB_VFS_OP_RENAME,
743 SMB_VFS_LAYER_TRANSPARENT},
744 {SMB_VFS_OP(streams_depot_streaminfo), SMB_VFS_OP_STREAMINFO,
745 SMB_VFS_LAYER_OPAQUE},
746 {SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP}
749 NTSTATUS vfs_streams_depot_init(void);
750 NTSTATUS vfs_streams_depot_init(void)
752 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "streams_depot",