source: trunk/server/source3/smbd/notify.c@ 480

Last change on this file since 480 was 414, checked in by Herwig Bauernfeind, 15 years ago

Samba 3.5.0: Initial import
File size: 14.3 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3 change notify handling
4 Copyright (C) Andrew Tridgell 2000
5 Copyright (C) Jeremy Allison 1994-1998
6 Copyright (C) Volker Lendecke 2007
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 "smbd/globals.h"
24
25struct notify_change_request {
26 struct notify_change_request *prev, *next;
27 struct files_struct *fsp; /* backpointer for cancel by mid */
28 struct smb_request *req;
29 uint32 filter;
30 uint32 max_param;
31 void (*reply_fn)(struct smb_request *req,
32 NTSTATUS error_code,
33 uint8_t *buf, size_t len);
34 struct notify_mid_map *mid_map;
35 void *backend_data;
36};
37
38static void notify_fsp(files_struct *fsp, uint32 action, const char *name);
39
40/*
41 * For NTCancel, we need to find the notify_change_request indexed by
42 * mid. Separate list here.
43 */
44
45struct notify_mid_map {
46 struct notify_mid_map *prev, *next;
47 struct notify_change_request *req;
48 uint16 mid;
49};
50
51static bool notify_change_record_identical(struct notify_change *c1,
52 struct notify_change *c2)
53{
54 /* Note this is deliberately case sensitive. */
55 if (c1->action == c2->action &&
56 strcmp(c1->name, c2->name) == 0) {
57 return True;
58 }
59 return False;
60}
61
62static bool notify_marshall_changes(int num_changes,
63 uint32 max_offset,
64 struct notify_change *changes,
65 prs_struct *ps)
66{
67 int i;
68 UNISTR uni_name;
69
70 if (num_changes == -1) {
71 return false;
72 }
73
74 uni_name.buffer = NULL;
75
76 for (i=0; i<num_changes; i++) {
77 struct notify_change *c;
78 size_t namelen;
79 uint32 u32_tmp; /* Temp arg to prs_uint32 to avoid
80 * signed/unsigned issues */
81
82 /* Coalesce any identical records. */
83 while (i+1 < num_changes &&
84 notify_change_record_identical(&changes[i],
85 &changes[i+1])) {
86 i++;
87 }
88
89 c = &changes[i];
90
91 if (!convert_string_talloc(talloc_tos(), CH_UNIX, CH_UTF16LE,
92 c->name, strlen(c->name)+1, &uni_name.buffer,
93 &namelen, True) || (uni_name.buffer == NULL)) {
94 goto fail;
95 }
96
97 namelen -= 2; /* Dump NULL termination */
98
99 /*
100 * Offset to next entry, only if there is one
101 */
102
103 u32_tmp = (i == num_changes-1) ? 0 : namelen + 12;
104 if (!prs_uint32("offset", ps, 1, &u32_tmp)) goto fail;
105
106 u32_tmp = c->action;
107 if (!prs_uint32("action", ps, 1, &u32_tmp)) goto fail;
108
109 u32_tmp = namelen;
110 if (!prs_uint32("namelen", ps, 1, &u32_tmp)) goto fail;
111
112 if (!prs_unistr("name", ps, 1, &uni_name)) goto fail;
113
114 /*
115 * Not NULL terminated, decrease by the 2 UCS2 \0 chars
116 */
117 prs_set_offset(ps, prs_offset(ps)-2);
118
119 TALLOC_FREE(uni_name.buffer);
120
121 if (prs_offset(ps) > max_offset) {
122 /* Too much data for client. */
123 DEBUG(10, ("Client only wanted %d bytes, trying to "
124 "marshall %d bytes\n", (int)max_offset,
125 (int)prs_offset(ps)));
126 return False;
127 }
128 }
129
130 return True;
131
132 fail:
133 TALLOC_FREE(uni_name.buffer);
134 return False;
135}
136
137/****************************************************************************
138 Setup the common parts of the return packet and send it.
139*****************************************************************************/
140
141void change_notify_reply(connection_struct *conn,
142 struct smb_request *req,
143 NTSTATUS error_code,
144 uint32_t max_param,
145 struct notify_change_buf *notify_buf,
146 void (*reply_fn)(struct smb_request *req,
147 NTSTATUS error_code,
148 uint8_t *buf, size_t len))
149{
150 prs_struct ps;
151
152 if (!NT_STATUS_IS_OK(error_code)) {
153 reply_fn(req, error_code, NULL, 0);
154 return;
155 }
156
157 if (max_param == 0 || notify_buf == NULL) {
158 reply_fn(req, NT_STATUS_OK, NULL, 0);
159 return;
160 }
161
162 prs_init_empty(&ps, NULL, MARSHALL);
163
164 if (!notify_marshall_changes(notify_buf->num_changes, max_param,
165 notify_buf->changes, &ps)) {
166 /*
167 * We exceed what the client is willing to accept. Send
168 * nothing.
169 */
170 prs_mem_free(&ps);
171 prs_init_empty(&ps, NULL, MARSHALL);
172 }
173
174 reply_fn(req, NT_STATUS_OK, (uint8_t *)prs_data_p(&ps), prs_offset(&ps));
175
176 prs_mem_free(&ps);
177
178 TALLOC_FREE(notify_buf->changes);
179 notify_buf->num_changes = 0;
180}
181
182static void notify_callback(void *private_data, const struct notify_event *e)
183{
184 files_struct *fsp = (files_struct *)private_data;
185 DEBUG(10, ("notify_callback called for %s\n", fsp_str_dbg(fsp)));
186 notify_fsp(fsp, e->action, e->path);
187}
188
189NTSTATUS change_notify_create(struct files_struct *fsp, uint32 filter,
190 bool recursive)
191{
192 char *fullpath;
193 struct notify_entry e;
194 NTSTATUS status;
195
196 SMB_ASSERT(fsp->notify == NULL);
197
198 if (!(fsp->notify = TALLOC_ZERO_P(NULL, struct notify_change_buf))) {
199 DEBUG(0, ("talloc failed\n"));
200 return NT_STATUS_NO_MEMORY;
201 }
202
203 /* Do notify operations on the base_name. */
204 if (asprintf(&fullpath, "%s/%s", fsp->conn->connectpath,
205 fsp->fsp_name->base_name) == -1) {
206 DEBUG(0, ("asprintf failed\n"));
207 TALLOC_FREE(fsp->notify);
208 return NT_STATUS_NO_MEMORY;
209 }
210
211 ZERO_STRUCT(e);
212 e.path = fullpath;
213 e.dir_fd = fsp->fh->fd;
214 e.dir_id = fsp->file_id;
215 e.filter = filter;
216 e.subdir_filter = 0;
217 if (recursive) {
218 e.subdir_filter = filter;
219 }
220
221 status = notify_add(fsp->conn->notify_ctx, &e, notify_callback, fsp);
222 SAFE_FREE(fullpath);
223
224 return status;
225}
226
227NTSTATUS change_notify_add_request(struct smb_request *req,
228 uint32 max_param,
229 uint32 filter, bool recursive,
230 struct files_struct *fsp,
231 void (*reply_fn)(struct smb_request *req,
232 NTSTATUS error_code,
233 uint8_t *buf, size_t len))
234{
235 struct notify_change_request *request = NULL;
236 struct notify_mid_map *map = NULL;
237 struct smbd_server_connection *sconn = smbd_server_conn;
238
239 DEBUG(10, ("change_notify_add_request: Adding request for %s: "
240 "max_param = %d\n", fsp_str_dbg(fsp), (int)max_param));
241
242 if (!(request = talloc(NULL, struct notify_change_request))
243 || !(map = talloc(request, struct notify_mid_map))) {
244 TALLOC_FREE(request);
245 return NT_STATUS_NO_MEMORY;
246 }
247
248 request->mid_map = map;
249 map->req = request;
250
251 request->req = talloc_move(request, &req);
252 request->max_param = max_param;
253 request->filter = filter;
254 request->fsp = fsp;
255 request->reply_fn = reply_fn;
256 request->backend_data = NULL;
257
258 DLIST_ADD_END(fsp->notify->requests, request,
259 struct notify_change_request *);
260
261 map->mid = request->req->mid;
262 DLIST_ADD(sconn->smb1.notify_mid_maps, map);
263
264 return NT_STATUS_OK;
265}
266
267static void change_notify_remove_request(struct notify_change_request *remove_req)
268{
269 files_struct *fsp;
270 struct notify_change_request *req;
271 struct smbd_server_connection *sconn = smbd_server_conn;
272
273 /*
274 * Paranoia checks, the fsp referenced must must have the request in
275 * its list of pending requests
276 */
277
278 fsp = remove_req->fsp;
279 SMB_ASSERT(fsp->notify != NULL);
280
281 for (req = fsp->notify->requests; req; req = req->next) {
282 if (req == remove_req) {
283 break;
284 }
285 }
286
287 if (req == NULL) {
288 smb_panic("notify_req not found in fsp's requests");
289 }
290
291 DLIST_REMOVE(fsp->notify->requests, req);
292 DLIST_REMOVE(sconn->smb1.notify_mid_maps, req->mid_map);
293 TALLOC_FREE(req);
294}
295
296/****************************************************************************
297 Delete entries by mid from the change notify pending queue. Always send reply.
298*****************************************************************************/
299
300void remove_pending_change_notify_requests_by_mid(uint16 mid)
301{
302 struct notify_mid_map *map;
303 struct smbd_server_connection *sconn = smbd_server_conn;
304
305 for (map = sconn->smb1.notify_mid_maps; map; map = map->next) {
306 if (map->mid == mid) {
307 break;
308 }
309 }
310
311 if (map == NULL) {
312 return;
313 }
314
315 change_notify_reply(map->req->fsp->conn, map->req->req,
316 NT_STATUS_CANCELLED, 0, NULL, map->req->reply_fn);
317 change_notify_remove_request(map->req);
318}
319
320void smbd_notify_cancel_by_smbreq(struct smbd_server_connection *sconn,
321 const struct smb_request *smbreq)
322{
323 struct notify_mid_map *map;
324
325 for (map = sconn->smb1.notify_mid_maps; map; map = map->next) {
326 if (map->req->req == smbreq) {
327 break;
328 }
329 }
330
331 if (map == NULL) {
332 return;
333 }
334
335 change_notify_reply(map->req->fsp->conn, map->req->req,
336 NT_STATUS_CANCELLED, 0, NULL, map->req->reply_fn);
337 change_notify_remove_request(map->req);
338}
339
340/****************************************************************************
341 Delete entries by fnum from the change notify pending queue.
342*****************************************************************************/
343
344void remove_pending_change_notify_requests_by_fid(files_struct *fsp,
345 NTSTATUS status)
346{
347 if (fsp->notify == NULL) {
348 return;
349 }
350
351 while (fsp->notify->requests != NULL) {
352 change_notify_reply(fsp->conn, fsp->notify->requests->req,
353 status, 0, NULL,
354 fsp->notify->requests->reply_fn);
355 change_notify_remove_request(fsp->notify->requests);
356 }
357}
358
359void notify_fname(connection_struct *conn, uint32 action, uint32 filter,
360 const char *path)
361{
362 char *fullpath;
363 char *parent;
364 const char *name;
365
366 if (path[0] == '.' && path[1] == '/') {
367 path += 2;
368 }
369 if (parent_dirname(talloc_tos(), path, &parent, &name)) {
370 struct smb_filename smb_fname_parent;
371
372 ZERO_STRUCT(smb_fname_parent);
373 smb_fname_parent.base_name = parent;
374
375 if (SMB_VFS_STAT(conn, &smb_fname_parent) != -1) {
376 notify_onelevel(conn->notify_ctx, action, filter,
377 SMB_VFS_FILE_ID_CREATE(conn, &smb_fname_parent.st),
378 name);
379 }
380 }
381
382 fullpath = talloc_asprintf(talloc_tos(), "%s/%s", conn->connectpath,
383 path);
384 if (fullpath == NULL) {
385 DEBUG(0, ("asprintf failed\n"));
386 return;
387 }
388 notify_trigger(conn->notify_ctx, action, filter, fullpath);
389 TALLOC_FREE(fullpath);
390}
391
392static void notify_fsp(files_struct *fsp, uint32 action, const char *name)
393{
394 struct notify_change *change, *changes;
395 char *tmp;
396
397 if (fsp->notify == NULL) {
398 /*
399 * Nobody is waiting, don't queue
400 */
401 return;
402 }
403
404 /*
405 * Someone has triggered a notify previously, queue the change for
406 * later.
407 */
408
409 if ((fsp->notify->num_changes > 1000) || (name == NULL)) {
410 /*
411 * The real number depends on the client buf, just provide a
412 * guard against a DoS here. If name == NULL the CN backend is
413 * alerting us to a problem. Possibly dropped events. Clear
414 * queued changes and send the catch-all response to the client
415 * if a request is pending.
416 */
417 TALLOC_FREE(fsp->notify->changes);
418 fsp->notify->num_changes = -1;
419 if (fsp->notify->requests != NULL) {
420 change_notify_reply(fsp->conn,
421 fsp->notify->requests->req,
422 NT_STATUS_OK,
423 fsp->notify->requests->max_param,
424 fsp->notify,
425 fsp->notify->requests->reply_fn);
426 change_notify_remove_request(fsp->notify->requests);
427 }
428 return;
429 }
430
431 /* If we've exceeded the server side queue or received a NULL name
432 * from the underlying CN implementation, don't queue up any more
433 * requests until we can send a catch-all response to the client */
434 if (fsp->notify->num_changes == -1) {
435 return;
436 }
437
438 if (!(changes = TALLOC_REALLOC_ARRAY(
439 fsp->notify, fsp->notify->changes,
440 struct notify_change, fsp->notify->num_changes+1))) {
441 DEBUG(0, ("talloc_realloc failed\n"));
442 return;
443 }
444
445 fsp->notify->changes = changes;
446
447 change = &(fsp->notify->changes[fsp->notify->num_changes]);
448
449 if (!(tmp = talloc_strdup(changes, name))) {
450 DEBUG(0, ("talloc_strdup failed\n"));
451 return;
452 }
453
454 string_replace(tmp, '/', '\\');
455 change->name = tmp;
456
457 change->action = action;
458 fsp->notify->num_changes += 1;
459
460 if (fsp->notify->requests == NULL) {
461 /*
462 * Nobody is waiting, so don't send anything. The ot
463 */
464 return;
465 }
466
467 if (action == NOTIFY_ACTION_OLD_NAME) {
468 /*
469 * We have to send the two rename events in one reply. So hold
470 * the first part back.
471 */
472 return;
473 }
474
475 /*
476 * Someone is waiting for the change, trigger the reply immediately.
477 *
478 * TODO: do we have to walk the lists of requests pending?
479 */
480
481 change_notify_reply(fsp->conn,
482 fsp->notify->requests->req,
483 NT_STATUS_OK,
484 fsp->notify->requests->max_param,
485 fsp->notify,
486 fsp->notify->requests->reply_fn);
487
488 change_notify_remove_request(fsp->notify->requests);
489}
490
491char *notify_filter_string(TALLOC_CTX *mem_ctx, uint32 filter)
492{
493 char *result = NULL;
494
495 result = talloc_strdup(mem_ctx, "");
496
497 if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
498 result = talloc_asprintf_append(result, "FILE_NAME|");
499 if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
500 result = talloc_asprintf_append(result, "DIR_NAME|");
501 if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
502 result = talloc_asprintf_append(result, "ATTRIBUTES|");
503 if (filter & FILE_NOTIFY_CHANGE_SIZE)
504 result = talloc_asprintf_append(result, "SIZE|");
505 if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
506 result = talloc_asprintf_append(result, "LAST_WRITE|");
507 if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
508 result = talloc_asprintf_append(result, "LAST_ACCESS|");
509 if (filter & FILE_NOTIFY_CHANGE_CREATION)
510 result = talloc_asprintf_append(result, "CREATION|");
511 if (filter & FILE_NOTIFY_CHANGE_EA)
512 result = talloc_asprintf_append(result, "EA|");
513 if (filter & FILE_NOTIFY_CHANGE_SECURITY)
514 result = talloc_asprintf_append(result, "SECURITY|");
515 if (filter & FILE_NOTIFY_CHANGE_STREAM_NAME)
516 result = talloc_asprintf_append(result, "STREAM_NAME|");
517 if (filter & FILE_NOTIFY_CHANGE_STREAM_SIZE)
518 result = talloc_asprintf_append(result, "STREAM_SIZE|");
519 if (filter & FILE_NOTIFY_CHANGE_STREAM_WRITE)
520 result = talloc_asprintf_append(result, "STREAM_WRITE|");
521
522 if (result == NULL) return NULL;
523 if (*result == '\0') return result;
524
525 result[strlen(result)-1] = '\0';
526 return result;
527}
528
529struct sys_notify_context *sys_notify_context_create(connection_struct *conn,
530 TALLOC_CTX *mem_ctx,
531 struct event_context *ev)
532{
533 struct sys_notify_context *ctx;
534
535 if (!(ctx = TALLOC_P(mem_ctx, struct sys_notify_context))) {
536 DEBUG(0, ("talloc failed\n"));
537 return NULL;
538 }
539
540 ctx->ev = ev;
541 ctx->conn = conn;
542 ctx->private_data = NULL;
543 return ctx;
544}
545
546NTSTATUS sys_notify_watch(struct sys_notify_context *ctx,
547 struct notify_entry *e,
548 void (*callback)(struct sys_notify_context *ctx,
549 void *private_data,
550 struct notify_event *ev),
551 void *private_data, void *handle)
552{
553 return SMB_VFS_NOTIFY_WATCH(ctx->conn, ctx, e, callback, private_data,
554 handle);
555}
556
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