source: branches/samba-3.2.x/source/modules/vfs_streams_depot.c

Last change on this file was 233, checked in by Herwig Bauernfeind, 16 years ago

Update 3.2 branch to 3.2.9
File size: 17.6 KB
Line 
1/*
2 * Store streams in a separate subdirectory
3 *
4 * Copyright (C) Volker Lendecke, 2007
5 *
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.
10 *
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.
15 *
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/>.
18 */
19
20#include "includes.h"
21
22#undef DBGC_CLASS
23#define DBGC_CLASS DBGC_VFS
24
25/*
26 * Excerpt from a mail from tridge:
27 *
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
31 *
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
34 * name.
35 */
36
37static uint32_t hash_fn(DATA_BLOB key)
38{
39 uint32_t value; /* Used to compute the hash value. */
40 uint32_t i; /* Used to cycle through random values. */
41
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)));
45
46 return (1103515243 * value + 12345);
47}
48
49/*
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.
56 *
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
60 * directory.
61 *
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.
66 */
67
68#define SAMBA_XATTR_MARKER "user.SAMBA_STREAMS"
69
70static bool file_is_valid(vfs_handle_struct *handle, const char *path,
71 bool check_valid)
72{
73 char buf;
74
75 if (!check_valid) {
76 return true;
77 }
78
79 DEBUG(10, ("file_is_valid (%s) called\n", path));
80
81 if (SMB_VFS_GETXATTR(handle->conn, path, SAMBA_XATTR_MARKER,
82 &buf, sizeof(buf)) != sizeof(buf)) {
83 DEBUG(10, ("GETXATTR failed: %s\n", strerror(errno)));
84 return false;
85 }
86
87 if (buf != '1') {
88 DEBUG(10, ("got wrong buffer content: '%c'\n", buf));
89 return false;
90 }
91
92 return true;
93}
94
95static bool mark_file_valid(vfs_handle_struct *handle, const char *path,
96 bool check_valid)
97{
98 char buf = '1';
99 int ret;
100
101 if (!check_valid) {
102 return true;
103 }
104
105 DEBUG(10, ("marking file %s as valid\n", path));
106
107 ret = SMB_VFS_SETXATTR(handle->conn, path, SAMBA_XATTR_MARKER,
108 &buf, sizeof(buf), 0);
109
110 if (ret == -1) {
111 DEBUG(10, ("SETXATTR failed: %s\n", strerror(errno)));
112 return false;
113 }
114
115 return true;
116}
117
118static char *stream_dir(vfs_handle_struct *handle, const char *base_path,
119 const SMB_STRUCT_STAT *base_sbuf, bool create_it)
120{
121 uint32_t hash;
122 char *result = NULL;
123 SMB_STRUCT_STAT sbuf;
124 uint8_t first, second;
125 char *tmp;
126 char *id_hex;
127 struct file_id id;
128 uint8 id_buf[16];
129 bool check_valid;
130 const char *rootdir;
131
132 check_valid = lp_parm_bool(SNUM(handle->conn),
133 "streams_depot", "check_valid", true);
134
135 tmp = talloc_asprintf(talloc_tos(), "%s/.streams", handle->conn->connectpath);
136
137 if (tmp == NULL) {
138 errno = ENOMEM;
139 goto fail;
140 }
141
142 rootdir = lp_parm_const_string(
143 SNUM(handle->conn), "streams_depot", "directory",
144 tmp);
145
146 if (base_sbuf == NULL) {
147 if (SMB_VFS_NEXT_STAT(handle, base_path, &sbuf) == -1) {
148 /*
149 * base file is not there
150 */
151 goto fail;
152 }
153 base_sbuf = &sbuf;
154 }
155
156 id = SMB_VFS_FILE_ID_CREATE(handle->conn, base_sbuf->st_dev,
157 base_sbuf->st_ino);
158
159 push_file_id_16((char *)id_buf, &id);
160
161 hash = hash_fn(data_blob_const(id_buf, sizeof(id_buf)));
162
163 first = hash & 0xff;
164 second = (hash >> 8) & 0xff;
165
166 id_hex = hex_encode(talloc_tos(), id_buf, sizeof(id_buf));
167
168 if (id_hex == NULL) {
169 errno = ENOMEM;
170 goto fail;
171 }
172
173 result = talloc_asprintf(talloc_tos(), "%s/%2.2X/%2.2X/%s", rootdir,
174 first, second, id_hex);
175
176 TALLOC_FREE(id_hex);
177
178 if (result == NULL) {
179 errno = ENOMEM;
180 return NULL;
181 }
182
183 if (SMB_VFS_NEXT_STAT(handle, result, &sbuf) == 0) {
184 char *newname;
185
186 if (!S_ISDIR(sbuf.st_mode)) {
187 errno = EINVAL;
188 goto fail;
189 }
190
191 if (file_is_valid(handle, base_path, check_valid)) {
192 return result;
193 }
194
195 /*
196 * Someone has recreated a file under an existing inode
197 * without deleting the streams directory. For now, just move
198 * it away.
199 */
200
201 again:
202 newname = talloc_asprintf(talloc_tos(), "lost-%lu", random());
203 if (newname == NULL) {
204 errno = ENOMEM;
205 goto fail;
206 }
207
208 if (SMB_VFS_NEXT_RENAME(handle, result, newname) == -1) {
209 if ((errno == EEXIST) || (errno == ENOTEMPTY)) {
210 TALLOC_FREE(newname);
211 goto again;
212 }
213 goto fail;
214 }
215
216 TALLOC_FREE(newname);
217 }
218
219 if (!create_it) {
220 errno = ENOENT;
221 goto fail;
222 }
223
224 if ((SMB_VFS_NEXT_MKDIR(handle, rootdir, 0755) != 0)
225 && (errno != EEXIST)) {
226 goto fail;
227 }
228
229 tmp = talloc_asprintf(result, "%s/%2.2X", rootdir, first);
230 if (tmp == NULL) {
231 errno = ENOMEM;
232 goto fail;
233 }
234
235 if ((SMB_VFS_NEXT_MKDIR(handle, tmp, 0755) != 0)
236 && (errno != EEXIST)) {
237 goto fail;
238 }
239
240 TALLOC_FREE(tmp);
241
242 tmp = talloc_asprintf(result, "%s/%2.2X/%2.2X", rootdir, first,
243 second);
244 if (tmp == NULL) {
245 errno = ENOMEM;
246 goto fail;
247 }
248
249 if ((SMB_VFS_NEXT_MKDIR(handle, tmp, 0755) != 0)
250 && (errno != EEXIST)) {
251 goto fail;
252 }
253
254 TALLOC_FREE(tmp);
255
256 if ((SMB_VFS_NEXT_MKDIR(handle, result, 0755) != 0)
257 && (errno != EEXIST)) {
258 goto fail;
259 }
260
261 if (!mark_file_valid(handle, base_path, check_valid)) {
262 goto fail;
263 }
264
265 return result;
266
267 fail:
268 TALLOC_FREE(result);
269 return NULL;
270}
271
272static char *stream_name(vfs_handle_struct *handle, const char *fname,
273 bool create_dir)
274{
275 char *base = NULL;
276 char *sname = NULL;
277 char *id_hex = NULL;
278 char *dirname, *stream_fname;
279
280 if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), fname,
281 &base, &sname))) {
282 DEBUG(10, ("split_ntfs_stream_name failed\n"));
283 errno = ENOMEM;
284 goto fail;
285 }
286
287 /* if it's the ::$DATA stream just return the base file name */
288 if (!sname) {
289 return base;
290 }
291
292 dirname = stream_dir(handle, base, NULL, create_dir);
293
294 if (dirname == NULL) {
295 goto fail;
296 }
297
298 stream_fname = talloc_asprintf(talloc_tos(), "%s/:%s", dirname, sname);
299
300 if (stream_fname == NULL) {
301 errno = ENOMEM;
302 goto fail;
303 }
304
305 DEBUG(10, ("stream filename = %s\n", stream_fname));
306
307 TALLOC_FREE(base);
308 TALLOC_FREE(sname);
309 TALLOC_FREE(id_hex);
310
311 return stream_fname;
312
313 fail:
314 DEBUG(5, ("stream_name failed: %s\n", strerror(errno)));
315 TALLOC_FREE(base);
316 TALLOC_FREE(sname);
317 TALLOC_FREE(id_hex);
318 return NULL;
319}
320
321static NTSTATUS walk_streams(vfs_handle_struct *handle,
322 const char *fname,
323 const SMB_STRUCT_STAT *sbuf,
324 char **pdirname,
325 bool (*fn)(const char *dirname,
326 const char *dirent,
327 void *private_data),
328 void *private_data)
329{
330 char *dirname;
331 SMB_STRUCT_DIR *dirhandle = NULL;
332 char *dirent;
333
334 dirname = stream_dir(handle, fname, sbuf, false);
335
336 if (dirname == NULL) {
337 if (errno == ENOENT) {
338 /*
339 * no stream around
340 */
341 return NT_STATUS_OK;
342 }
343 return map_nt_error_from_unix(errno);
344 }
345
346 DEBUG(10, ("walk_streams: dirname=%s\n", dirname));
347
348 dirhandle = SMB_VFS_NEXT_OPENDIR(handle, dirname, NULL, 0);
349
350 if (dirhandle == NULL) {
351 TALLOC_FREE(dirname);
352 return map_nt_error_from_unix(errno);
353 }
354
355 while ((dirent = vfs_readdirname(handle->conn, dirhandle)) != NULL) {
356
357 if (ISDOT(dirent) || ISDOTDOT(dirent)) {
358 continue;
359 }
360
361 DEBUG(10, ("walk_streams: dirent=%s\n", dirent));
362
363 if (!fn(dirname, dirent, private_data)) {
364 break;
365 }
366 }
367
368 SMB_VFS_NEXT_CLOSEDIR(handle, dirhandle);
369
370 if (pdirname != NULL) {
371 *pdirname = dirname;
372 }
373 else {
374 TALLOC_FREE(dirname);
375 }
376
377 return NT_STATUS_OK;
378}
379
380static int streams_depot_stat(vfs_handle_struct *handle, const char *fname,
381 SMB_STRUCT_STAT *sbuf)
382{
383 char *stream_fname;
384 int ret = -1;
385
386 DEBUG(10, ("streams_depot_stat called for [%s]\n", fname));
387
388 if (!is_ntfs_stream_name(fname)) {
389 return SMB_VFS_NEXT_STAT(handle, fname, sbuf);
390 }
391
392 stream_fname = stream_name(handle, fname, false);
393 if (stream_fname == NULL) {
394 goto done;
395 }
396
397 ret = SMB_VFS_NEXT_STAT(handle, stream_fname, sbuf);
398
399 done:
400 TALLOC_FREE(stream_fname);
401 return ret;
402}
403
404static int streams_depot_lstat(vfs_handle_struct *handle, const char *fname,
405 SMB_STRUCT_STAT *sbuf)
406{
407 char *stream_fname;
408 int ret = -1;
409
410 if (!is_ntfs_stream_name(fname)) {
411 return SMB_VFS_NEXT_LSTAT(handle, fname, sbuf);
412 }
413
414 stream_fname = stream_name(handle, fname, false);
415 if (stream_fname == NULL) {
416 goto done;
417 }
418
419 ret = SMB_VFS_NEXT_LSTAT(handle, stream_fname, sbuf);
420
421 done:
422 TALLOC_FREE(stream_fname);
423 return ret;
424}
425
426static int streams_depot_open(vfs_handle_struct *handle, const char *fname,
427 files_struct *fsp, int flags, mode_t mode)
428{
429 TALLOC_CTX *frame;
430 char *base = NULL;
431 char *sname = NULL;
432 SMB_STRUCT_STAT base_sbuf;
433 char *stream_fname;
434 int ret = -1;
435
436 if (!is_ntfs_stream_name(fname)) {
437 return SMB_VFS_NEXT_OPEN(handle, fname, fsp, flags, mode);
438 }
439
440 frame = talloc_stackframe();
441
442 if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), fname,
443 &base, &sname))) {
444 errno = ENOMEM;
445 goto done;
446 }
447
448 if (!sname) {
449 ret = SMB_VFS_NEXT_OPEN(handle, base, fsp, flags, mode);
450 goto done;
451 }
452
453 ret = SMB_VFS_NEXT_STAT(handle, base, &base_sbuf);
454
455 if (ret == -1) {
456 goto done;
457 }
458
459 TALLOC_FREE(base);
460
461 stream_fname = stream_name(handle, fname, true);
462 if (stream_fname == NULL) {
463 goto done;
464 }
465
466 ret = SMB_VFS_NEXT_OPEN(handle, stream_fname, fsp, flags, mode);
467
468 done:
469 TALLOC_FREE(frame);
470 return ret;
471}
472
473static int streams_depot_unlink(vfs_handle_struct *handle, const char *fname)
474{
475 int ret = -1;
476 SMB_STRUCT_STAT sbuf;
477
478 DEBUG(10, ("streams_depot_unlink called for %s\n", fname));
479
480 if (is_ntfs_stream_name(fname)) {
481 char *stream_fname;
482
483 stream_fname = stream_name(handle, fname, false);
484 if (stream_fname == NULL) {
485 return -1;
486 }
487
488 ret = SMB_VFS_NEXT_UNLINK(handle, stream_fname);
489
490 TALLOC_FREE(stream_fname);
491 return ret;
492 }
493
494 /*
495 * We potentially need to delete the per-inode streams directory
496 */
497
498 if (lp_posix_pathnames()) {
499 ret = SMB_VFS_NEXT_LSTAT(handle, fname, &sbuf);
500 } else {
501 ret = SMB_VFS_NEXT_STAT(handle, fname, &sbuf);
502 }
503
504 if (ret == -1) {
505 return -1;
506 }
507
508 if (sbuf.st_nlink == 1) {
509 char *dirname = stream_dir(handle, fname, &sbuf, false);
510
511 if (dirname != NULL) {
512 SMB_VFS_NEXT_RMDIR(handle, dirname);
513 }
514 TALLOC_FREE(dirname);
515 }
516
517 return SMB_VFS_NEXT_UNLINK(handle, fname);
518}
519
520static int streams_depot_rename(vfs_handle_struct *handle,
521 const char *oldname,
522 const char *newname)
523{
524 TALLOC_CTX *frame = NULL;
525 int ret = -1;
526 bool old_is_stream;
527 bool new_is_stream;
528 char *obase = NULL;
529 char *osname = NULL;
530 char *nbase = NULL;
531 char *nsname = NULL;
532 char *ostream_fname = NULL;
533 char *nstream_fname = NULL;
534 char *newname_full = NULL;
535
536 DEBUG(10, ("streams_depot_rename called for %s => %s\n",
537 oldname, newname));
538
539 old_is_stream = is_ntfs_stream_name(oldname);
540 new_is_stream = is_ntfs_stream_name(newname);
541
542 if (!old_is_stream && !new_is_stream) {
543 return SMB_VFS_NEXT_RENAME(handle, oldname, newname);
544 }
545
546 frame = talloc_stackframe();
547
548 if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), oldname,
549 &obase, &osname))) {
550 errno = ENOMEM;
551 goto done;
552 }
553
554 if (!NT_STATUS_IS_OK(split_ntfs_stream_name(talloc_tos(), newname,
555 &nbase, &nsname))) {
556 errno = ENOMEM;
557 goto done;
558 }
559
560 /* for now don't allow renames from or to the default stream */
561 if (!osname || !nsname) {
562 errno = ENOSYS;
563 goto done;
564 }
565
566 ostream_fname = stream_name(handle, oldname, false);
567 if (ostream_fname == NULL) {
568 return -1;
569 }
570
571 /*
572 * Handle passing in a stream name without the base file. This is
573 * exercised by the NTRENAME streams rename path.
574 */
575 if (StrCaseCmp(nbase, "./") == 0) {
576 newname_full = talloc_asprintf(talloc_tos(), "%s:%s", obase,
577 nsname);
578 if (newname_full == NULL) {
579 errno = ENOMEM;
580 goto done;
581 }
582 }
583
584 nstream_fname = stream_name(handle,
585 newname_full ? newname_full : newname,
586 false);
587 if (nstream_fname == NULL) {
588 return -1;
589 }
590
591 ret = SMB_VFS_NEXT_RENAME(handle, ostream_fname, nstream_fname);
592
593done:
594 TALLOC_FREE(frame);
595 return ret;
596}
597
598static bool add_one_stream(TALLOC_CTX *mem_ctx, unsigned int *num_streams,
599 struct stream_struct **streams,
600 const char *name, SMB_OFF_T size,
601 SMB_OFF_T alloc_size)
602{
603 struct stream_struct *tmp;
604
605 tmp = TALLOC_REALLOC_ARRAY(mem_ctx, *streams, struct stream_struct,
606 (*num_streams)+1);
607 if (tmp == NULL) {
608 return false;
609 }
610
611 tmp[*num_streams].name = talloc_strdup(tmp, name);
612 if (tmp[*num_streams].name == NULL) {
613 return false;
614 }
615
616 tmp[*num_streams].size = size;
617 tmp[*num_streams].alloc_size = alloc_size;
618
619 *streams = tmp;
620 *num_streams += 1;
621 return true;
622}
623
624struct streaminfo_state {
625 TALLOC_CTX *mem_ctx;
626 vfs_handle_struct *handle;
627 unsigned int num_streams;
628 struct stream_struct *streams;
629 NTSTATUS status;
630};
631
632static bool collect_one_stream(const char *dirname,
633 const char *dirent,
634 void *private_data)
635{
636 struct streaminfo_state *state =
637 (struct streaminfo_state *)private_data;
638 char *full_sname;
639 SMB_STRUCT_STAT sbuf;
640
641 if (asprintf(&full_sname, "%s/%s", dirname, dirent) == -1) {
642 state->status = NT_STATUS_NO_MEMORY;
643 return false;
644 }
645 if (SMB_VFS_NEXT_STAT(state->handle, full_sname, &sbuf) == -1) {
646 DEBUG(10, ("Could not stat %s: %s\n", full_sname,
647 strerror(errno)));
648 SAFE_FREE(full_sname);
649 return true;
650 }
651
652 SAFE_FREE(full_sname);
653
654 if (!add_one_stream(state->mem_ctx,
655 &state->num_streams, &state->streams,
656 dirent, sbuf.st_size,
657 get_allocation_size(
658 state->handle->conn, NULL, &sbuf))) {
659 state->status = NT_STATUS_NO_MEMORY;
660 return false;
661 }
662
663 return true;
664}
665
666static NTSTATUS streams_depot_streaminfo(vfs_handle_struct *handle,
667 struct files_struct *fsp,
668 const char *fname,
669 TALLOC_CTX *mem_ctx,
670 unsigned int *pnum_streams,
671 struct stream_struct **pstreams)
672{
673 SMB_STRUCT_STAT sbuf;
674 int ret;
675 NTSTATUS status;
676 struct streaminfo_state state;
677
678 if ((fsp != NULL) && (fsp->fh->fd != -1)) {
679 if (is_ntfs_stream_name(fsp->fsp_name)) {
680 return NT_STATUS_INVALID_PARAMETER;
681 }
682 ret = SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf);
683 }
684 else {
685 if (is_ntfs_stream_name(fname)) {
686 return NT_STATUS_INVALID_PARAMETER;
687 }
688 if (lp_posix_pathnames()) {
689 ret = SMB_VFS_NEXT_LSTAT(handle, fname, &sbuf);
690 } else {
691 ret = SMB_VFS_NEXT_STAT(handle, fname, &sbuf);
692 }
693 }
694
695 if (ret == -1) {
696 return map_nt_error_from_unix(errno);
697 }
698
699 state.streams = NULL;
700 state.num_streams = 0;
701
702 if (!S_ISDIR(sbuf.st_mode)) {
703 if (!add_one_stream(mem_ctx,
704 &state.num_streams, &state.streams,
705 "::$DATA", sbuf.st_size,
706 get_allocation_size(handle->conn, fsp,
707 &sbuf))) {
708 return NT_STATUS_NO_MEMORY;
709 }
710 }
711
712 state.mem_ctx = mem_ctx;
713 state.handle = handle;
714 state.status = NT_STATUS_OK;
715
716 status = walk_streams(handle, fname, &sbuf, NULL, collect_one_stream,
717 &state);
718
719 if (!NT_STATUS_IS_OK(status)) {
720 TALLOC_FREE(state.streams);
721 return status;
722 }
723
724 if (!NT_STATUS_IS_OK(state.status)) {
725 TALLOC_FREE(state.streams);
726 return state.status;
727 }
728
729 *pnum_streams = state.num_streams;
730 *pstreams = state.streams;
731 return NT_STATUS_OK;
732}
733
734static uint32_t streams_depot_fs_capabilities(struct vfs_handle_struct *handle)
735{
736 return SMB_VFS_NEXT_FS_CAPABILITIES(handle) | FILE_NAMED_STREAMS;
737}
738
739/* VFS operations structure */
740
741static vfs_op_tuple streams_depot_ops[] = {
742 {SMB_VFS_OP(streams_depot_fs_capabilities), SMB_VFS_OP_FS_CAPABILITIES,
743 SMB_VFS_LAYER_TRANSPARENT},
744 {SMB_VFS_OP(streams_depot_open), SMB_VFS_OP_OPEN,
745 SMB_VFS_LAYER_TRANSPARENT},
746 {SMB_VFS_OP(streams_depot_stat), SMB_VFS_OP_STAT,
747 SMB_VFS_LAYER_TRANSPARENT},
748 {SMB_VFS_OP(streams_depot_lstat), SMB_VFS_OP_LSTAT,
749 SMB_VFS_LAYER_TRANSPARENT},
750 {SMB_VFS_OP(streams_depot_unlink), SMB_VFS_OP_UNLINK,
751 SMB_VFS_LAYER_TRANSPARENT},
752 {SMB_VFS_OP(streams_depot_rename), SMB_VFS_OP_RENAME,
753 SMB_VFS_LAYER_TRANSPARENT},
754 {SMB_VFS_OP(streams_depot_streaminfo), SMB_VFS_OP_STREAMINFO,
755 SMB_VFS_LAYER_OPAQUE},
756 {SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP}
757};
758
759NTSTATUS vfs_streams_depot_init(void);
760NTSTATUS vfs_streams_depot_init(void)
761{
762 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "streams_depot",
763 streams_depot_ops);
764}
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