source: trunk/server/source4/ntvfs/posix/pvfs_streams.c

Last change on this file was 745, checked in by Silvan Scherrer, 13 years ago

Samba Server: updated trunk to 3.6.0
File size: 13.9 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3
4 POSIX NTVFS backend - alternate data streams
5
6 Copyright (C) Andrew Tridgell 2004
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>.
20*/
21
22#include "includes.h"
23#include "vfs_posix.h"
24#include "librpc/gen_ndr/xattr.h"
25
26/*
27 normalise a stream name, removing a :$DATA suffix if there is one
28 Note: this returns the existing pointer to the name if the name does
29 not need normalising
30 */
31static const char *stream_name_normalise(TALLOC_CTX *ctx, const char *name)
32{
33 const char *c = strchr_m(name, ':');
34 if (c == NULL || strcasecmp_m(c, ":$DATA") != 0) {
35 return name;
36 }
37 return talloc_strndup(ctx, name, c-name);
38}
39
40/*
41 compare two stream names, taking account of the default $DATA extension
42 */
43static int stream_name_cmp(const char *name1, const char *name2)
44{
45 const char *c1, *c2;
46 int l1, l2, ret;
47 c1 = strchr_m(name1, ':');
48 c2 = strchr_m(name2, ':');
49
50 /* check the first part is the same */
51 l1 = c1?(c1 - name1):strlen(name1);
52 l2 = c2?(c2 - name2):strlen(name2);
53 if (l1 != l2) {
54 return l1 - l2;
55 }
56 ret = strncasecmp_m(name1, name2, l1);
57 if (ret != 0) {
58 return ret;
59 }
60
61 /* the first parts are the same, check the suffix */
62 if (c1 && c2) {
63 return strcasecmp_m(c1, c2);
64 }
65
66 if (c1) {
67 return strcasecmp_m(c1, ":$DATA");
68 }
69 if (c2) {
70 return strcasecmp_m(c2, ":$DATA");
71 }
72
73 /* neither names have a suffix */
74 return 0;
75}
76
77
78/*
79 return the list of file streams for RAW_FILEINFO_STREAM_INFORMATION
80*/
81NTSTATUS pvfs_stream_information(struct pvfs_state *pvfs,
82 TALLOC_CTX *mem_ctx,
83 struct pvfs_filename *name, int fd,
84 struct stream_information *info)
85{
86 struct xattr_DosStreams *streams;
87 int i;
88 NTSTATUS status;
89
90 /* directories don't have streams */
91 if (name->dos.attrib & FILE_ATTRIBUTE_DIRECTORY) {
92 info->num_streams = 0;
93 info->streams = NULL;
94 return NT_STATUS_OK;
95 }
96
97 streams = talloc(mem_ctx, struct xattr_DosStreams);
98 if (streams == NULL) {
99 return NT_STATUS_NO_MEMORY;
100 }
101
102 status = pvfs_streams_load(pvfs, name, fd, streams);
103 if (!NT_STATUS_IS_OK(status)) {
104 ZERO_STRUCTP(streams);
105 }
106
107 info->num_streams = streams->num_streams+1;
108 info->streams = talloc_array(mem_ctx, struct stream_struct, info->num_streams);
109 if (!info->streams) {
110 return NT_STATUS_NO_MEMORY;
111 }
112
113 info->streams[0].size = name->st.st_size;
114 info->streams[0].alloc_size = name->dos.alloc_size;
115 info->streams[0].stream_name.s = talloc_strdup(info->streams, "::$DATA");
116
117 for (i=0;i<streams->num_streams;i++) {
118 info->streams[i+1].size = streams->streams[i].size;
119 info->streams[i+1].alloc_size = streams->streams[i].alloc_size;
120 if (strchr(streams->streams[i].name, ':') == NULL) {
121 info->streams[i+1].stream_name.s = talloc_asprintf(streams->streams,
122 ":%s:$DATA",
123 streams->streams[i].name);
124 } else {
125 info->streams[i+1].stream_name.s = talloc_strdup(streams->streams,
126 streams->streams[i].name);
127 }
128 }
129
130 return NT_STATUS_OK;
131}
132
133
134/*
135 fill in the stream information for a name
136*/
137NTSTATUS pvfs_stream_info(struct pvfs_state *pvfs, struct pvfs_filename *name, int fd)
138{
139 struct xattr_DosStreams *streams;
140 int i;
141 NTSTATUS status;
142
143 /* the NULL stream always exists */
144 if (name->stream_name == NULL) {
145 name->stream_exists = true;
146 return NT_STATUS_OK;
147 }
148
149 streams = talloc(name, struct xattr_DosStreams);
150 if (streams == NULL) {
151 return NT_STATUS_NO_MEMORY;
152 }
153
154 status = pvfs_streams_load(pvfs, name, fd, streams);
155 if (!NT_STATUS_IS_OK(status)) {
156 talloc_free(streams);
157 return status;
158 }
159
160 for (i=0;i<streams->num_streams;i++) {
161 struct xattr_DosStream *s = &streams->streams[i];
162 if (stream_name_cmp(s->name, name->stream_name) == 0) {
163 name->dos.alloc_size = pvfs_round_alloc_size(pvfs, s->alloc_size);
164 name->st.st_size = s->size;
165 name->stream_exists = true;
166 talloc_free(streams);
167 return NT_STATUS_OK;
168 }
169 }
170
171 talloc_free(streams);
172
173 name->dos.alloc_size = 0;
174 name->st.st_size = 0;
175 name->stream_exists = false;
176
177 return NT_STATUS_OK;
178}
179
180
181/*
182 update size information for a stream
183*/
184static NTSTATUS pvfs_stream_update_size(struct pvfs_state *pvfs, struct pvfs_filename *name, int fd,
185 off_t size)
186{
187 struct xattr_DosStreams *streams;
188 int i;
189 NTSTATUS status;
190
191 streams = talloc(name, struct xattr_DosStreams);
192 if (streams == NULL) {
193 return NT_STATUS_NO_MEMORY;
194 }
195
196 status = pvfs_streams_load(pvfs, name, fd, streams);
197 if (!NT_STATUS_IS_OK(status)) {
198 ZERO_STRUCTP(streams);
199 }
200
201 for (i=0;i<streams->num_streams;i++) {
202 struct xattr_DosStream *s = &streams->streams[i];
203 if (stream_name_cmp(s->name, name->stream_name) == 0) {
204 s->size = size;
205 s->alloc_size = pvfs_round_alloc_size(pvfs, size);
206 break;
207 }
208 }
209
210 if (i == streams->num_streams) {
211 struct xattr_DosStream *s;
212 streams->streams = talloc_realloc(streams, streams->streams,
213 struct xattr_DosStream,
214 streams->num_streams+1);
215 if (streams->streams == NULL) {
216 talloc_free(streams);
217 return NT_STATUS_NO_MEMORY;
218 }
219 streams->num_streams++;
220 s = &streams->streams[i];
221
222 s->flags = XATTR_STREAM_FLAG_INTERNAL;
223 s->size = size;
224 s->alloc_size = pvfs_round_alloc_size(pvfs, size);
225 s->name = stream_name_normalise(streams, name->stream_name);
226 if (s->name == NULL) {
227 talloc_free(streams);
228 return NT_STATUS_NO_MEMORY;
229 }
230 }
231
232 status = pvfs_streams_save(pvfs, name, fd, streams);
233 talloc_free(streams);
234
235 return status;
236}
237
238
239/*
240 rename a stream
241*/
242NTSTATUS pvfs_stream_rename(struct pvfs_state *pvfs, struct pvfs_filename *name, int fd,
243 const char *new_name, bool overwrite)
244{
245 struct xattr_DosStreams *streams;
246 int i, found_old, found_new;
247 NTSTATUS status;
248
249 streams = talloc(name, struct xattr_DosStreams);
250 if (streams == NULL) {
251 return NT_STATUS_NO_MEMORY;
252 }
253
254 new_name = stream_name_normalise(streams, new_name);
255 if (new_name == NULL) {
256 return NT_STATUS_NO_MEMORY;
257 }
258
259 status = pvfs_streams_load(pvfs, name, fd, streams);
260 if (!NT_STATUS_IS_OK(status)) {
261 ZERO_STRUCTP(streams);
262 }
263
264 /* the default stream always exists */
265 if (strcmp(new_name, "") == 0 ||
266 strcasecmp_m(new_name, ":$DATA") == 0) {
267 return NT_STATUS_OBJECT_NAME_COLLISION;
268 }
269
270 /* try to find the old/new names in the list */
271 found_old = found_new = -1;
272 for (i=0;i<streams->num_streams;i++) {
273 struct xattr_DosStream *s = &streams->streams[i];
274 if (stream_name_cmp(s->name, new_name) == 0) {
275 found_new = i;
276 }
277 if (stream_name_cmp(s->name, name->stream_name) == 0) {
278 found_old = i;
279 }
280 }
281
282 if (found_old == -1) {
283 talloc_free(streams);
284 return NT_STATUS_OBJECT_NAME_NOT_FOUND;
285 }
286
287 if (found_new == -1) {
288 /* a simple rename */
289 struct xattr_DosStream *s = &streams->streams[found_old];
290 s->name = new_name;
291 } else {
292 if (!overwrite) {
293 return NT_STATUS_OBJECT_NAME_COLLISION;
294 }
295 if (found_old != found_new) {
296 /* remove the old one and replace with the new one */
297 streams->streams[found_old].name = new_name;
298 memmove(&streams->streams[found_new],
299 &streams->streams[found_new+1],
300 sizeof(streams->streams[0]) *
301 (streams->num_streams - (found_new+1)));
302 streams->num_streams--;
303 }
304 }
305
306 status = pvfs_streams_save(pvfs, name, fd, streams);
307
308 if (NT_STATUS_IS_OK(status)) {
309
310 /* update the in-memory copy of the name of the open file */
311 talloc_free(name->stream_name);
312 name->stream_name = talloc_strdup(name, new_name);
313
314 talloc_free(streams);
315 }
316
317 return status;
318}
319
320
321/*
322 create the xattr for a alternate data stream
323*/
324NTSTATUS pvfs_stream_create(struct pvfs_state *pvfs,
325 struct pvfs_filename *name,
326 int fd)
327{
328 NTSTATUS status;
329 status = pvfs_xattr_create(pvfs, name->full_name, fd,
330 XATTR_DOSSTREAM_PREFIX, name->stream_name);
331 if (!NT_STATUS_IS_OK(status)) {
332 return status;
333 }
334 return pvfs_stream_update_size(pvfs, name, fd, 0);
335}
336
337/*
338 delete the xattr for a alternate data stream
339*/
340NTSTATUS pvfs_stream_delete(struct pvfs_state *pvfs,
341 struct pvfs_filename *name,
342 int fd)
343{
344 NTSTATUS status;
345 struct xattr_DosStreams *streams;
346 int i;
347
348 status = pvfs_xattr_delete(pvfs, name->full_name, fd,
349 XATTR_DOSSTREAM_PREFIX, name->stream_name);
350 if (!NT_STATUS_IS_OK(status)) {
351 return status;
352 }
353
354 streams = talloc(name, struct xattr_DosStreams);
355 if (streams == NULL) {
356 return NT_STATUS_NO_MEMORY;
357 }
358
359 status = pvfs_streams_load(pvfs, name, fd, streams);
360 if (!NT_STATUS_IS_OK(status)) {
361 talloc_free(streams);
362 return status;
363 }
364
365 for (i=0;i<streams->num_streams;i++) {
366 struct xattr_DosStream *s = &streams->streams[i];
367 if (stream_name_cmp(s->name, name->stream_name) == 0) {
368 memmove(s, s+1, (streams->num_streams - (i+1)) * sizeof(*s));
369 streams->num_streams--;
370 break;
371 }
372 }
373
374 status = pvfs_streams_save(pvfs, name, fd, streams);
375 talloc_free(streams);
376
377 return status;
378}
379
380/*
381 load a stream into a blob
382*/
383static NTSTATUS pvfs_stream_load(struct pvfs_state *pvfs,
384 TALLOC_CTX *mem_ctx,
385 struct pvfs_filename *name,
386 int fd,
387 size_t estimated_size,
388 DATA_BLOB *blob)
389{
390 NTSTATUS status;
391
392 status = pvfs_xattr_load(pvfs, mem_ctx, name->full_name, fd,
393 XATTR_DOSSTREAM_PREFIX,
394 name->stream_name, estimated_size, blob);
395
396 if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
397 /* try with a case insensitive match */
398 struct xattr_DosStreams *streams;
399 int i;
400
401 streams = talloc(mem_ctx, struct xattr_DosStreams);
402 if (streams == NULL) {
403 return NT_STATUS_NO_MEMORY;
404 }
405
406 status = pvfs_streams_load(pvfs, name, fd, streams);
407 if (!NT_STATUS_IS_OK(status)) {
408 talloc_free(streams);
409 return NT_STATUS_NOT_FOUND;
410 }
411 for (i=0;i<streams->num_streams;i++) {
412 struct xattr_DosStream *s = &streams->streams[i];
413 if (stream_name_cmp(s->name, name->stream_name) == 0) {
414 status = pvfs_xattr_load(pvfs, mem_ctx, name->full_name, fd,
415 XATTR_DOSSTREAM_PREFIX,
416 s->name, estimated_size, blob);
417 talloc_free(streams);
418 return status;
419 }
420 }
421 talloc_free(streams);
422 return NT_STATUS_NOT_FOUND;
423 }
424
425 return status;
426}
427
428/*
429 the equvalent of pread() on a stream
430*/
431ssize_t pvfs_stream_read(struct pvfs_state *pvfs,
432 struct pvfs_file_handle *h, void *data, size_t count, off_t offset)
433{
434 NTSTATUS status;
435 DATA_BLOB blob;
436 if (count == 0) {
437 return 0;
438 }
439 status = pvfs_stream_load(pvfs, h, h->name, h->fd, offset+count, &blob);
440 if (!NT_STATUS_IS_OK(status)) {
441 errno = EIO;
442 return -1;
443 }
444 if (offset >= blob.length) {
445 data_blob_free(&blob);
446 return 0;
447 }
448 if (count > blob.length - offset) {
449 count = blob.length - offset;
450 }
451 memcpy(data, blob.data + offset, count);
452 data_blob_free(&blob);
453 return count;
454}
455
456
457/*
458 the equvalent of pwrite() on a stream
459*/
460ssize_t pvfs_stream_write(struct pvfs_state *pvfs,
461 struct pvfs_file_handle *h, const void *data, size_t count, off_t offset)
462{
463 NTSTATUS status;
464 DATA_BLOB blob;
465 if (count == 0) {
466 return 0;
467 }
468
469 if (count+offset > XATTR_MAX_STREAM_SIZE) {
470 if (!pvfs->ea_db || count+offset > XATTR_MAX_STREAM_SIZE_TDB) {
471 errno = ENOSPC;
472 return -1;
473 }
474 }
475
476 /* we have to load the existing stream, then modify, then save */
477 status = pvfs_stream_load(pvfs, h, h->name, h->fd, offset+count, &blob);
478 if (!NT_STATUS_IS_OK(status)) {
479 blob = data_blob(NULL, 0);
480 }
481 if (count+offset > blob.length) {
482 blob.data = talloc_realloc(blob.data, blob.data, uint8_t, count+offset);
483 if (blob.data == NULL) {
484 errno = ENOMEM;
485 return -1;
486 }
487 if (offset > blob.length) {
488 memset(blob.data+blob.length, 0, offset - blob.length);
489 }
490 blob.length = count+offset;
491 }
492 memcpy(blob.data + offset, data, count);
493
494 status = pvfs_xattr_save(pvfs, h->name->full_name, h->fd, XATTR_DOSSTREAM_PREFIX,
495 h->name->stream_name, &blob);
496 if (!NT_STATUS_IS_OK(status)) {
497 data_blob_free(&blob);
498 /* getting this error mapping right is probably
499 not worth it */
500 errno = ENOSPC;
501 return -1;
502 }
503
504 status = pvfs_stream_update_size(pvfs, h->name, h->fd, blob.length);
505
506 data_blob_free(&blob);
507
508 if (!NT_STATUS_IS_OK(status)) {
509 errno = EIO;
510 return -1;
511 }
512
513 return count;
514}
515
516/*
517 the equvalent of truncate() on a stream
518*/
519NTSTATUS pvfs_stream_truncate(struct pvfs_state *pvfs,
520 struct pvfs_filename *name, int fd, off_t length)
521{
522 NTSTATUS status;
523 DATA_BLOB blob;
524
525 if (length > XATTR_MAX_STREAM_SIZE) {
526 if (!pvfs->ea_db || length > XATTR_MAX_STREAM_SIZE_TDB) {
527 return NT_STATUS_DISK_FULL;
528 }
529 }
530
531 /* we have to load the existing stream, then modify, then save */
532 status = pvfs_stream_load(pvfs, name, name, fd, length, &blob);
533 if (!NT_STATUS_IS_OK(status)) {
534 return status;
535 }
536 if (length <= blob.length) {
537 blob.length = length;
538 } else if (length > blob.length) {
539 blob.data = talloc_realloc(blob.data, blob.data, uint8_t, length);
540 if (blob.data == NULL) {
541 return NT_STATUS_NO_MEMORY;
542 }
543 memset(blob.data+blob.length, 0, length - blob.length);
544 blob.length = length;
545 }
546
547 status = pvfs_xattr_save(pvfs, name->full_name, fd, XATTR_DOSSTREAM_PREFIX,
548 name->stream_name, &blob);
549
550 if (NT_STATUS_IS_OK(status)) {
551 status = pvfs_stream_update_size(pvfs, name, fd, blob.length);
552 }
553 data_blob_free(&blob);
554
555 return status;
556}
Note: See TracBrowser for help on using the repository browser.