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DEFINITIONS
This source file includes following definitions.
- notify_change_record_identical
- notify_marshall_changes
- change_notify_reply_packet
- change_notify_reply
- notify_callback
- change_notify_create
- change_notify_add_request
- change_notify_remove_request
- remove_pending_change_notify_requests_by_mid
- remove_pending_change_notify_requests_by_fid
- notify_fname
- notify_fsp
- notify_filter_string
- sys_notify_context_create
- sys_notify_watch
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
25 struct 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 struct notify_mid_map *mid_map;
32 void *backend_data;
33 };
34
35 static void notify_fsp(files_struct *fsp, uint32 action, const char *name);
36
37 /*
38 * For NTCancel, we need to find the notify_change_request indexed by
39 * mid. Separate list here.
40 */
41
42 struct notify_mid_map {
43 struct notify_mid_map *prev, *next;
44 struct notify_change_request *req;
45 uint16 mid;
46 };
47
48 static bool notify_change_record_identical(struct notify_change *c1,
/* [<][>][^][v][top][bottom][index][help] */
49 struct notify_change *c2)
50 {
51 /* Note this is deliberately case sensitive. */
52 if (c1->action == c2->action &&
53 strcmp(c1->name, c2->name) == 0) {
54 return True;
55 }
56 return False;
57 }
58
59 static bool notify_marshall_changes(int num_changes,
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60 uint32 max_offset,
61 struct notify_change *changes,
62 prs_struct *ps)
63 {
64 int i;
65 UNISTR uni_name;
66
67 uni_name.buffer = NULL;
68
69 for (i=0; i<num_changes; i++) {
70 struct notify_change *c;
71 size_t namelen;
72 uint32 u32_tmp; /* Temp arg to prs_uint32 to avoid
73 * signed/unsigned issues */
74
75 /* Coalesce any identical records. */
76 while (i+1 < num_changes &&
77 notify_change_record_identical(&changes[i],
78 &changes[i+1])) {
79 i++;
80 }
81
82 c = &changes[i];
83
84 if (!convert_string_allocate(NULL, CH_UNIX, CH_UTF16LE,
85 c->name, strlen(c->name)+1, &uni_name.buffer,
86 &namelen, True) || (uni_name.buffer == NULL)) {
87 goto fail;
88 }
89
90 namelen -= 2; /* Dump NULL termination */
91
92 /*
93 * Offset to next entry, only if there is one
94 */
95
96 u32_tmp = (i == num_changes-1) ? 0 : namelen + 12;
97 if (!prs_uint32("offset", ps, 1, &u32_tmp)) goto fail;
98
99 u32_tmp = c->action;
100 if (!prs_uint32("action", ps, 1, &u32_tmp)) goto fail;
101
102 u32_tmp = namelen;
103 if (!prs_uint32("namelen", ps, 1, &u32_tmp)) goto fail;
104
105 if (!prs_unistr("name", ps, 1, &uni_name)) goto fail;
106
107 /*
108 * Not NULL terminated, decrease by the 2 UCS2 \0 chars
109 */
110 prs_set_offset(ps, prs_offset(ps)-2);
111
112 SAFE_FREE(uni_name.buffer);
113
114 if (prs_offset(ps) > max_offset) {
115 /* Too much data for client. */
116 DEBUG(10, ("Client only wanted %d bytes, trying to "
117 "marshall %d bytes\n", (int)max_offset,
118 (int)prs_offset(ps)));
119 return False;
120 }
121 }
122
123 return True;
124
125 fail:
126 SAFE_FREE(uni_name.buffer);
127 return False;
128 }
129
130 /****************************************************************************
131 Setup the common parts of the return packet and send it.
132 *****************************************************************************/
133
134 static void change_notify_reply_packet(connection_struct *conn,
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135 struct smb_request *req,
136 NTSTATUS error_code)
137 {
138 reply_outbuf(req, 18, 0);
139
140 if (!NT_STATUS_IS_OK(error_code)) {
141 error_packet_set((char *)req->outbuf, 0, 0, error_code,
142 __LINE__,__FILE__);
143 }
144
145 show_msg((char *)req->outbuf);
146 if (!srv_send_smb(smbd_server_fd(), (char *)req->outbuf,
147 req->encrypted, &req->pcd)) {
148 exit_server_cleanly("change_notify_reply_packet: srv_send_smb "
149 "failed.");
150 }
151 TALLOC_FREE(req->outbuf);
152 }
153
154 void change_notify_reply(connection_struct *conn,
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155 struct smb_request *req, uint32 max_param,
156 struct notify_change_buf *notify_buf)
157 {
158 prs_struct ps;
159
160 if (notify_buf->num_changes == -1) {
161 change_notify_reply_packet(conn, req, NT_STATUS_OK);
162 notify_buf->num_changes = 0;
163 return;
164 }
165
166 prs_init_empty(&ps, NULL, MARSHALL);
167
168 if (!notify_marshall_changes(notify_buf->num_changes, max_param,
169 notify_buf->changes, &ps)) {
170 /*
171 * We exceed what the client is willing to accept. Send
172 * nothing.
173 */
174 change_notify_reply_packet(conn, req, NT_STATUS_OK);
175 goto done;
176 }
177
178 send_nt_replies(conn, req, NT_STATUS_OK, prs_data_p(&ps),
179 prs_offset(&ps), NULL, 0);
180
181 done:
182 prs_mem_free(&ps);
183
184 TALLOC_FREE(notify_buf->changes);
185 notify_buf->num_changes = 0;
186 }
187
188 static void notify_callback(void *private_data, const struct notify_event *e)
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189 {
190 files_struct *fsp = (files_struct *)private_data;
191 DEBUG(10, ("notify_callback called for %s\n", fsp->fsp_name));
192 notify_fsp(fsp, e->action, e->path);
193 }
194
195 NTSTATUS change_notify_create(struct files_struct *fsp, uint32 filter,
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196 bool recursive)
197 {
198 char *fullpath;
199 struct notify_entry e;
200 NTSTATUS status;
201
202 SMB_ASSERT(fsp->notify == NULL);
203
204 if (!(fsp->notify = TALLOC_ZERO_P(NULL, struct notify_change_buf))) {
205 DEBUG(0, ("talloc failed\n"));
206 return NT_STATUS_NO_MEMORY;
207 }
208
209 if (asprintf(&fullpath, "%s/%s", fsp->conn->connectpath,
210 fsp->fsp_name) == -1) {
211 DEBUG(0, ("asprintf failed\n"));
212 TALLOC_FREE(fsp->notify);
213 return NT_STATUS_NO_MEMORY;
214 }
215
216 ZERO_STRUCT(e);
217 e.path = fullpath;
218 e.dir_fd = fsp->fh->fd;
219 e.dir_id = fsp->file_id;
220 e.filter = filter;
221 e.subdir_filter = 0;
222 if (recursive) {
223 e.subdir_filter = filter;
224 }
225
226 status = notify_add(fsp->conn->notify_ctx, &e, notify_callback, fsp);
227 SAFE_FREE(fullpath);
228
229 return status;
230 }
231
232 NTSTATUS change_notify_add_request(struct smb_request *req,
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233 uint32 max_param,
234 uint32 filter, bool recursive,
235 struct files_struct *fsp)
236 {
237 struct notify_change_request *request = NULL;
238 struct notify_mid_map *map = NULL;
239
240 DEBUG(10, ("change_notify_add_request: Adding request for %s: "
241 "max_param = %d\n", fsp->fsp_name, (int)max_param));
242
243 if (!(request = talloc(NULL, struct notify_change_request))
244 || !(map = talloc(request, struct notify_mid_map))) {
245 TALLOC_FREE(request);
246 return NT_STATUS_NO_MEMORY;
247 }
248
249 request->mid_map = map;
250 map->req = request;
251
252 request->req = talloc_move(request, &req);
253 request->max_param = max_param;
254 request->filter = filter;
255 request->fsp = fsp;
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(notify_changes_by_mid, map);
263
264 /* Push the MID of this packet on the signing queue. */
265 srv_defer_sign_response(request->req->mid);
266
267 return NT_STATUS_OK;
268 }
269
270 static void change_notify_remove_request(struct notify_change_request *remove_req)
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271 {
272 files_struct *fsp;
273 struct notify_change_request *req;
274
275 /*
276 * Paranoia checks, the fsp referenced must must have the request in
277 * its list of pending requests
278 */
279
280 fsp = remove_req->fsp;
281 SMB_ASSERT(fsp->notify != NULL);
282
283 for (req = fsp->notify->requests; req; req = req->next) {
284 if (req == remove_req) {
285 break;
286 }
287 }
288
289 if (req == NULL) {
290 smb_panic("notify_req not found in fsp's requests");
291 }
292
293 DLIST_REMOVE(fsp->notify->requests, req);
294 DLIST_REMOVE(notify_changes_by_mid, req->mid_map);
295 TALLOC_FREE(req);
296 }
297
298 /****************************************************************************
299 Delete entries by mid from the change notify pending queue. Always send reply.
300 *****************************************************************************/
301
302 void remove_pending_change_notify_requests_by_mid(uint16 mid)
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303 {
304 struct notify_mid_map *map;
305
306 for (map = notify_changes_by_mid; map; map = map->next) {
307 if (map->mid == mid) {
308 break;
309 }
310 }
311
312 if (map == NULL) {
313 return;
314 }
315
316 change_notify_reply_packet(map->req->fsp->conn, map->req->req,
317 NT_STATUS_CANCELLED);
318 change_notify_remove_request(map->req);
319 }
320
321 /****************************************************************************
322 Delete entries by fnum from the change notify pending queue.
323 *****************************************************************************/
324
325 void remove_pending_change_notify_requests_by_fid(files_struct *fsp,
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326 NTSTATUS status)
327 {
328 if (fsp->notify == NULL) {
329 return;
330 }
331
332 while (fsp->notify->requests != NULL) {
333 change_notify_reply_packet(
334 fsp->conn, fsp->notify->requests->req, status);
335 change_notify_remove_request(fsp->notify->requests);
336 }
337 }
338
339 void notify_fname(connection_struct *conn, uint32 action, uint32 filter,
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340 const char *path)
341 {
342 char *fullpath;
343
344 if (path[0] == '.' && path[1] == '/') {
345 path += 2;
346 }
347 if (asprintf(&fullpath, "%s/%s", conn->connectpath, path) == -1) {
348 DEBUG(0, ("asprintf failed\n"));
349 return;
350 }
351
352 notify_trigger(conn->notify_ctx, action, filter, fullpath);
353 SAFE_FREE(fullpath);
354 }
355
356 static void notify_fsp(files_struct *fsp, uint32 action, const char *name)
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357 {
358 struct notify_change *change, *changes;
359 char *tmp;
360
361 if (fsp->notify == NULL) {
362 /*
363 * Nobody is waiting, don't queue
364 */
365 return;
366 }
367
368 /*
369 * Someone has triggered a notify previously, queue the change for
370 * later.
371 */
372
373 if ((fsp->notify->num_changes > 1000) || (name == NULL)) {
374 /*
375 * The real number depends on the client buf, just provide a
376 * guard against a DoS here. If name == NULL the CN backend is
377 * alerting us to a problem. Possibly dropped events. Clear
378 * queued changes and send the catch-all response to the client
379 * if a request is pending.
380 */
381 TALLOC_FREE(fsp->notify->changes);
382 fsp->notify->num_changes = -1;
383 if (fsp->notify->requests != NULL) {
384 change_notify_reply(fsp->conn,
385 fsp->notify->requests->req,
386 fsp->notify->requests->max_param,
387 fsp->notify);
388 change_notify_remove_request(fsp->notify->requests);
389 }
390 return;
391 }
392
393 /* If we've exceeded the server side queue or received a NULL name
394 * from the underlying CN implementation, don't queue up any more
395 * requests until we can send a catch-all response to the client */
396 if (fsp->notify->num_changes == -1) {
397 return;
398 }
399
400 if (!(changes = TALLOC_REALLOC_ARRAY(
401 fsp->notify, fsp->notify->changes,
402 struct notify_change, fsp->notify->num_changes+1))) {
403 DEBUG(0, ("talloc_realloc failed\n"));
404 return;
405 }
406
407 fsp->notify->changes = changes;
408
409 change = &(fsp->notify->changes[fsp->notify->num_changes]);
410
411 if (!(tmp = talloc_strdup(changes, name))) {
412 DEBUG(0, ("talloc_strdup failed\n"));
413 return;
414 }
415
416 string_replace(tmp, '/', '\\');
417 change->name = tmp;
418
419 change->action = action;
420 fsp->notify->num_changes += 1;
421
422 if (fsp->notify->requests == NULL) {
423 /*
424 * Nobody is waiting, so don't send anything. The ot
425 */
426 return;
427 }
428
429 if (action == NOTIFY_ACTION_OLD_NAME) {
430 /*
431 * We have to send the two rename events in one reply. So hold
432 * the first part back.
433 */
434 return;
435 }
436
437 /*
438 * Someone is waiting for the change, trigger the reply immediately.
439 *
440 * TODO: do we have to walk the lists of requests pending?
441 */
442
443 change_notify_reply(fsp->conn,
444 fsp->notify->requests->req,
445 fsp->notify->requests->max_param,
446 fsp->notify);
447
448 change_notify_remove_request(fsp->notify->requests);
449 }
450
451 char *notify_filter_string(TALLOC_CTX *mem_ctx, uint32 filter)
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452 {
453 char *result = NULL;
454
455 result = talloc_strdup(mem_ctx, "");
456
457 if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
458 result = talloc_asprintf_append(result, "FILE_NAME|");
459 if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
460 result = talloc_asprintf_append(result, "DIR_NAME|");
461 if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
462 result = talloc_asprintf_append(result, "ATTRIBUTES|");
463 if (filter & FILE_NOTIFY_CHANGE_SIZE)
464 result = talloc_asprintf_append(result, "SIZE|");
465 if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
466 result = talloc_asprintf_append(result, "LAST_WRITE|");
467 if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
468 result = talloc_asprintf_append(result, "LAST_ACCESS|");
469 if (filter & FILE_NOTIFY_CHANGE_CREATION)
470 result = talloc_asprintf_append(result, "CREATION|");
471 if (filter & FILE_NOTIFY_CHANGE_EA)
472 result = talloc_asprintf_append(result, "EA|");
473 if (filter & FILE_NOTIFY_CHANGE_SECURITY)
474 result = talloc_asprintf_append(result, "SECURITY|");
475 if (filter & FILE_NOTIFY_CHANGE_STREAM_NAME)
476 result = talloc_asprintf_append(result, "STREAM_NAME|");
477 if (filter & FILE_NOTIFY_CHANGE_STREAM_SIZE)
478 result = talloc_asprintf_append(result, "STREAM_SIZE|");
479 if (filter & FILE_NOTIFY_CHANGE_STREAM_WRITE)
480 result = talloc_asprintf_append(result, "STREAM_WRITE|");
481
482 if (result == NULL) return NULL;
483 if (*result == '\0') return result;
484
485 result[strlen(result)-1] = '\0';
486 return result;
487 }
488
489 struct sys_notify_context *sys_notify_context_create(connection_struct *conn,
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490 TALLOC_CTX *mem_ctx,
491 struct event_context *ev)
492 {
493 struct sys_notify_context *ctx;
494
495 if (!(ctx = TALLOC_P(mem_ctx, struct sys_notify_context))) {
496 DEBUG(0, ("talloc failed\n"));
497 return NULL;
498 }
499
500 ctx->ev = ev;
501 ctx->conn = conn;
502 ctx->private_data = NULL;
503 return ctx;
504 }
505
506 NTSTATUS sys_notify_watch(struct sys_notify_context *ctx,
/* [<][>][^][v][top][bottom][index][help] */
507 struct notify_entry *e,
508 void (*callback)(struct sys_notify_context *ctx,
509 void *private_data,
510 struct notify_event *ev),
511 void *private_data, void *handle)
512 {
513 return SMB_VFS_NOTIFY_WATCH(ctx->conn, ctx, e, callback, private_data,
514 handle);
515 }
516