summaryrefslogtreecommitdiff
path: root/source3/smbd/notify.c
blob: 72872108029b5e1a4acac15a88ac1ad524a202d5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
/*
   Unix SMB/CIFS implementation.
   change notify handling
   Copyright (C) Andrew Tridgell 2000
   Copyright (C) Jeremy Allison 1994-1998
   Copyright (C) Volker Lendecke 2007

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"

struct notify_change_request {
	struct notify_change_request *prev, *next;
	struct files_struct *fsp;	/* backpointer for cancel by mid */
	uint8 request_buf[smb_size];
	uint32 filter;
	uint32 max_param;
	struct notify_mid_map *mid_map;
	void *backend_data;
};

static void notify_fsp(files_struct *fsp, uint32 action, const char *name);

static struct notify_mid_map *notify_changes_by_mid;

/*
 * For NTCancel, we need to find the notify_change_request indexed by
 * mid. Separate list here.
 */

struct notify_mid_map {
	struct notify_mid_map *prev, *next;
	struct notify_change_request *req;
	uint16 mid;
};

static bool notify_change_record_identical(struct notify_change *c1,
					struct notify_change *c2)
{
	/* Note this is deliberately case sensitive. */
	if (c1->action == c2->action &&
			strcmp(c1->name, c2->name) == 0) {
		return True;
	}
	return False;
}

static bool notify_marshall_changes(int num_changes,
				uint32 max_offset,
				struct notify_change *changes,
				prs_struct *ps)
{
	int i;
	UNISTR uni_name;

	for (i=0; i<num_changes; i++) {
		struct notify_change *c;
		size_t namelen;
		uint32 u32_tmp;	/* Temp arg to prs_uint32 to avoid
				 * signed/unsigned issues */

		/* Coalesce any identical records. */
		while (i+1 < num_changes &&
			notify_change_record_identical(&changes[i],
						&changes[i+1])) {
			i++;
		}

		c = &changes[i];

		namelen = convert_string_allocate(
			NULL, CH_UNIX, CH_UTF16LE, c->name, strlen(c->name)+1,
			&uni_name.buffer, True);
		if ((namelen == -1) || (uni_name.buffer == NULL)) {
			goto fail;
		}

		namelen -= 2;	/* Dump NULL termination */

		/*
		 * Offset to next entry, only if there is one
		 */

		u32_tmp = (i == num_changes-1) ? 0 : namelen + 12;
		if (!prs_uint32("offset", ps, 1, &u32_tmp)) goto fail;

		u32_tmp = c->action;
		if (!prs_uint32("action", ps, 1, &u32_tmp)) goto fail;

		u32_tmp = namelen;
		if (!prs_uint32("namelen", ps, 1, &u32_tmp)) goto fail;

		if (!prs_unistr("name", ps, 1, &uni_name)) goto fail;

		/*
		 * Not NULL terminated, decrease by the 2 UCS2 \0 chars
		 */
		prs_set_offset(ps, prs_offset(ps)-2);

		SAFE_FREE(uni_name.buffer);

		if (prs_offset(ps) > max_offset) {
			/* Too much data for client. */
			return False;
		}
	}

	return True;

 fail:
	SAFE_FREE(uni_name.buffer);
	return False;
}

/****************************************************************************
 Setup the common parts of the return packet and send it.
*****************************************************************************/

static void change_notify_reply_packet(connection_struct *conn,
				const uint8 *request_buf,
				       NTSTATUS error_code)
{
	char outbuf[smb_size+38];

	memset(outbuf, '\0', sizeof(outbuf));
	construct_reply_common((char *)request_buf, outbuf);

	ERROR_NT(error_code);

	/*
	 * Seems NT needs a transact command with an error code
	 * in it. This is a longer packet than a simple error.
	 */
	srv_set_message(outbuf,18,0,False);

	show_msg(outbuf);
	if (!srv_send_smb(smbd_server_fd(),
			outbuf,
			IS_CONN_ENCRYPTED(conn)))
		exit_server_cleanly("change_notify_reply_packet: srv_send_smb "
				    "failed.");
}

void change_notify_reply(connection_struct *conn,
			const uint8 *request_buf, uint32 max_param,
			 struct notify_change_buf *notify_buf)
{
	prs_struct ps;
	struct smb_request *req = NULL;
	uint8 tmp_request[smb_size];

	if (notify_buf->num_changes == -1) {
		change_notify_reply_packet(conn, request_buf, NT_STATUS_OK);
		notify_buf->num_changes = 0;
		return;
	}

	prs_init(&ps, 0, NULL, MARSHALL);

	if (!notify_marshall_changes(notify_buf->num_changes, max_param,
					notify_buf->changes, &ps)) {
		/*
		 * We exceed what the client is willing to accept. Send
		 * nothing.
		 */
		change_notify_reply_packet(conn, request_buf, NT_STATUS_OK);
		goto done;
	}

	if (!(req = talloc(talloc_tos(), struct smb_request))) {
		change_notify_reply_packet(conn, request_buf, NT_STATUS_NO_MEMORY);
		goto done;
	}

	memcpy(tmp_request, request_buf, smb_size);

	/*
	 * We're only interested in the header fields here
	 */

	smb_setlen((char *)tmp_request, smb_size);
	SCVAL(tmp_request, smb_wct, 0);

	init_smb_request(req, tmp_request,0, conn->encrypted_tid);

	send_nt_replies(conn, req, NT_STATUS_OK, prs_data_p(&ps),
			prs_offset(&ps), NULL, 0);

 done:
	TALLOC_FREE(req);
	prs_mem_free(&ps);

	TALLOC_FREE(notify_buf->changes);
	notify_buf->num_changes = 0;
}

static void notify_callback(void *private_data, const struct notify_event *e)
{
	files_struct *fsp = (files_struct *)private_data;
	DEBUG(10, ("notify_callback called for %s\n", fsp->fsp_name));
	notify_fsp(fsp, e->action, e->path);
}

NTSTATUS change_notify_create(struct files_struct *fsp, uint32 filter,
			      bool recursive)
{
	char *fullpath;
	struct notify_entry e;
	NTSTATUS status;

	SMB_ASSERT(fsp->notify == NULL);

	if (!(fsp->notify = TALLOC_ZERO_P(NULL, struct notify_change_buf))) {
		DEBUG(0, ("talloc failed\n"));
		return NT_STATUS_NO_MEMORY;
	}

	if (asprintf(&fullpath, "%s/%s", fsp->conn->connectpath,
		     fsp->fsp_name) == -1) {
		DEBUG(0, ("asprintf failed\n"));
		return NT_STATUS_NO_MEMORY;
	}

	e.path = fullpath;
	e.filter = filter;
	e.subdir_filter = 0;
	if (recursive) {
		e.subdir_filter = filter;
	}

	status = notify_add(fsp->conn->notify_ctx, &e, notify_callback, fsp);
	SAFE_FREE(fullpath);

	return status;
}

NTSTATUS change_notify_add_request(const struct smb_request *req,
				uint32 max_param,
				uint32 filter, bool recursive,
				struct files_struct *fsp)
{
	struct notify_change_request *request = NULL;
	struct notify_mid_map *map = NULL;

	if (!(request = SMB_MALLOC_P(struct notify_change_request))
	    || !(map = SMB_MALLOC_P(struct notify_mid_map))) {
		SAFE_FREE(request);
		return NT_STATUS_NO_MEMORY;
	}

	request->mid_map = map;
	map->req = request;

	memcpy(request->request_buf, req->inbuf, sizeof(request->request_buf));
	request->max_param = max_param;
	request->filter = filter;
	request->fsp = fsp;
	request->backend_data = NULL;

	DLIST_ADD_END(fsp->notify->requests, request,
		      struct notify_change_request *);

	map->mid = SVAL(req->inbuf, smb_mid);
	DLIST_ADD(notify_changes_by_mid, map);

	/* Push the MID of this packet on the signing queue. */
	srv_defer_sign_response(SVAL(req->inbuf,smb_mid));

	return NT_STATUS_OK;
}

static void change_notify_remove_request(struct notify_change_request *remove_req)
{
	files_struct *fsp;
	struct notify_change_request *req;

	/*
	 * Paranoia checks, the fsp referenced must must have the request in
	 * its list of pending requests
	 */

	fsp = remove_req->fsp;
	SMB_ASSERT(fsp->notify != NULL);

	for (req = fsp->notify->requests; req; req = req->next) {
		if (req == remove_req) {
			break;
		}
	}

	if (req == NULL) {
		smb_panic("notify_req not found in fsp's requests");
	}

	DLIST_REMOVE(fsp->notify->requests, req);
	DLIST_REMOVE(notify_changes_by_mid, req->mid_map);
	SAFE_FREE(req->mid_map);
	TALLOC_FREE(req->backend_data);
	SAFE_FREE(req);
}

/****************************************************************************
 Delete entries by mid from the change notify pending queue. Always send reply.
*****************************************************************************/

void remove_pending_change_notify_requests_by_mid(uint16 mid)
{
	struct notify_mid_map *map;

	for (map = notify_changes_by_mid; map; map = map->next) {
		if (map->mid == mid) {
			break;
		}
	}

	if (map == NULL) {
		return;
	}

	change_notify_reply_packet(map->req->fsp->conn,
			map->req->request_buf, NT_STATUS_CANCELLED);
	change_notify_remove_request(map->req);
}

/****************************************************************************
 Delete entries by fnum from the change notify pending queue.
*****************************************************************************/

void remove_pending_change_notify_requests_by_fid(files_struct *fsp,
						  NTSTATUS status)
{
	if (fsp->notify == NULL) {
		return;
	}

	while (fsp->notify->requests != NULL) {
		change_notify_reply_packet(fsp->conn,
			fsp->notify->requests->request_buf, status);
		change_notify_remove_request(fsp->notify->requests);
	}
}

void notify_fname(connection_struct *conn, uint32 action, uint32 filter,
		  const char *path)
{
	char *fullpath;

	if (asprintf(&fullpath, "%s/%s", conn->connectpath, path) == -1) {
		DEBUG(0, ("asprintf failed\n"));
		return;
	}

	notify_trigger(conn->notify_ctx, action, filter, fullpath);
	SAFE_FREE(fullpath);
}

static void notify_fsp(files_struct *fsp, uint32 action, const char *name)
{
	struct notify_change *change, *changes;
	char *tmp;

	if (fsp->notify == NULL) {
		/*
		 * Nobody is waiting, don't queue
		 */
		return;
	}

	/*
	 * Someone has triggered a notify previously, queue the change for
	 * later.
	 */

	if ((fsp->notify->num_changes > 1000) || (name == NULL)) {
		/*
		 * The real number depends on the client buf, just provide a
		 * guard against a DoS here.
		 */
		TALLOC_FREE(fsp->notify->changes);
		fsp->notify->num_changes = -1;
		return;
	}

	if (fsp->notify->num_changes == -1) {
		return;
	}

	if (!(changes = TALLOC_REALLOC_ARRAY(
		      fsp->notify, fsp->notify->changes,
		      struct notify_change, fsp->notify->num_changes+1))) {
		DEBUG(0, ("talloc_realloc failed\n"));
		return;
	}

	fsp->notify->changes = changes;

	change = &(fsp->notify->changes[fsp->notify->num_changes]);

	if (!(tmp = talloc_strdup(changes, name))) {
		DEBUG(0, ("talloc_strdup failed\n"));
		return;
	}

	string_replace(tmp, '/', '\\');
	change->name = tmp;	

	change->action = action;
	fsp->notify->num_changes += 1;

	if (fsp->notify->requests == NULL) {
		/*
		 * Nobody is waiting, so don't send anything. The ot
		 */
		return;
	}

	if (action == NOTIFY_ACTION_OLD_NAME) {
		/*
		 * We have to send the two rename events in one reply. So hold
		 * the first part back.
		 */
		return;
	}

	/*
	 * Someone is waiting for the change, trigger the reply immediately.
	 *
	 * TODO: do we have to walk the lists of requests pending?
	 */

	change_notify_reply(fsp->conn,
			fsp->notify->requests->request_buf,
			    fsp->notify->requests->max_param,
			    fsp->notify);

	change_notify_remove_request(fsp->notify->requests);
}

char *notify_filter_string(TALLOC_CTX *mem_ctx, uint32 filter)
{
	char *result = NULL;

	result = talloc_strdup(mem_ctx, "");

	if (filter & FILE_NOTIFY_CHANGE_FILE_NAME)
		result = talloc_asprintf_append(result, "FILE_NAME|");
	if (filter & FILE_NOTIFY_CHANGE_DIR_NAME)
		result = talloc_asprintf_append(result, "DIR_NAME|");
	if (filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)
		result = talloc_asprintf_append(result, "ATTRIBUTES|");
	if (filter & FILE_NOTIFY_CHANGE_SIZE)
		result = talloc_asprintf_append(result, "SIZE|");
	if (filter & FILE_NOTIFY_CHANGE_LAST_WRITE)
		result = talloc_asprintf_append(result, "LAST_WRITE|");
	if (filter & FILE_NOTIFY_CHANGE_LAST_ACCESS)
		result = talloc_asprintf_append(result, "LAST_ACCESS|");
	if (filter & FILE_NOTIFY_CHANGE_CREATION)
		result = talloc_asprintf_append(result, "CREATION|");
	if (filter & FILE_NOTIFY_CHANGE_EA)
		result = talloc_asprintf_append(result, "EA|");
	if (filter & FILE_NOTIFY_CHANGE_SECURITY)
		result = talloc_asprintf_append(result, "SECURITY|");
	if (filter & FILE_NOTIFY_CHANGE_STREAM_NAME)
		result = talloc_asprintf_append(result, "STREAM_NAME|");
	if (filter & FILE_NOTIFY_CHANGE_STREAM_SIZE)
		result = talloc_asprintf_append(result, "STREAM_SIZE|");
	if (filter & FILE_NOTIFY_CHANGE_STREAM_WRITE)
		result = talloc_asprintf_append(result, "STREAM_WRITE|");

	if (result == NULL) return NULL;
	if (*result == '\0') return result;

	result[strlen(result)-1] = '\0';
	return result;
}

struct sys_notify_context *sys_notify_context_create(connection_struct *conn,
						     TALLOC_CTX *mem_ctx, 
						     struct event_context *ev)
{
	struct sys_notify_context *ctx;

	if (!(ctx = TALLOC_P(mem_ctx, struct sys_notify_context))) {
		DEBUG(0, ("talloc failed\n"));
		return NULL;
	}

	ctx->ev = ev;
	ctx->conn = conn;
	ctx->private_data = NULL;
	return ctx;
}

NTSTATUS sys_notify_watch(struct sys_notify_context *ctx,
			  struct notify_entry *e,
			  void (*callback)(struct sys_notify_context *ctx, 
					   void *private_data,
					   struct notify_event *ev),
			  void *private_data, void *handle)
{
	return SMB_VFS_NOTIFY_WATCH(ctx->conn, ctx, e, callback, private_data,
				    handle);
}