1/*
2   Unix SMB/CIFS implementation.
3   Blocking Locking functions
4   Copyright (C) Jeremy Allison 1998-2003
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 2 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, write to the Free Software
18   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19*/
20
21#include "includes.h"
22#undef DBGC_CLASS
23#define DBGC_CLASS DBGC_LOCKING
24
25extern int max_send;
26
27/****************************************************************************
28 This is the structure to queue to implement blocking locks.
29 notify. It consists of the requesting SMB and the expiry time.
30*****************************************************************************/
31
32typedef struct _blocking_lock_record {
33	struct _blocking_lock_record *next;
34	struct _blocking_lock_record *prev;
35	int com_type;
36	files_struct *fsp;
37	struct timeval expire_time;
38	int lock_num;
39	SMB_BIG_UINT offset;
40	SMB_BIG_UINT count;
41	uint32 lock_pid;
42	uint32 blocking_pid; /* PID that blocks us. */
43	enum brl_flavour lock_flav;
44	enum brl_type lock_type;
45	char *inbuf;
46	int length;
47} blocking_lock_record;
48
49/* dlink list we store pending lock records on. */
50static blocking_lock_record *blocking_lock_queue;
51
52/* dlink list we move cancelled lock records onto. */
53static blocking_lock_record *blocking_lock_cancelled_queue;
54
55/****************************************************************************
56 Destructor for the above structure.
57****************************************************************************/
58
59static void free_blocking_lock_record(blocking_lock_record *blr)
60{
61	SAFE_FREE(blr->inbuf);
62	SAFE_FREE(blr);
63}
64
65/****************************************************************************
66 Determine if this is a secondary element of a chained SMB.
67  **************************************************************************/
68
69static BOOL in_chained_smb(void)
70{
71	return (chain_size != 0);
72}
73
74static void received_unlock_msg(int msg_type, struct process_id src,
75				void *buf, size_t len,
76				void *private_data);
77
78/****************************************************************************
79 Function to push a blocking lock request onto the lock queue.
80****************************************************************************/
81
82BOOL push_blocking_lock_request( struct byte_range_lock *br_lck,
83		char *inbuf, int length,
84		files_struct *fsp,
85		int lock_timeout,
86		int lock_num,
87		uint32 lock_pid,
88		enum brl_type lock_type,
89		enum brl_flavour lock_flav,
90		SMB_BIG_UINT offset,
91		SMB_BIG_UINT count,
92		uint32 blocking_pid)
93{
94	static BOOL set_lock_msg;
95	blocking_lock_record *blr;
96	NTSTATUS status;
97
98	if(in_chained_smb() ) {
99		DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
100		return False;
101	}
102
103	/*
104	 * Now queue an entry on the blocking lock queue. We setup
105	 * the expiration time here.
106	 */
107
108	if((blr = SMB_MALLOC_P(blocking_lock_record)) == NULL) {
109		DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
110		return False;
111	}
112
113	blr->next = NULL;
114	blr->prev = NULL;
115
116	if((blr->inbuf = (char *)SMB_MALLOC(length)) == NULL) {
117		DEBUG(0,("push_blocking_lock_request: Malloc fail (2)!\n" ));
118		SAFE_FREE(blr);
119		return False;
120	}
121
122	blr->com_type = CVAL(inbuf,smb_com);
123	blr->fsp = fsp;
124	if (lock_timeout == -1) {
125		blr->expire_time.tv_sec = 0;
126		blr->expire_time.tv_usec = 0; /* Never expire. */
127	} else {
128		blr->expire_time = timeval_current_ofs(lock_timeout/1000,
129					(lock_timeout % 1000) * 1000);
130	}
131	blr->lock_num = lock_num;
132	blr->lock_pid = lock_pid;
133	blr->blocking_pid = blocking_pid;
134	blr->lock_flav = lock_flav;
135	blr->lock_type = lock_type;
136	blr->offset = offset;
137	blr->count = count;
138	memcpy(blr->inbuf, inbuf, length);
139	blr->length = length;
140
141	/* Add a pending lock record for this. */
142	status = brl_lock(br_lck,
143			lock_pid,
144			procid_self(),
145			offset,
146			count,
147			lock_type == READ_LOCK ? PENDING_READ_LOCK : PENDING_WRITE_LOCK,
148			blr->lock_flav,
149			lock_timeout ? True : False, /* blocking_lock. */
150			NULL);
151
152	if (!NT_STATUS_IS_OK(status)) {
153		DEBUG(0,("push_blocking_lock_request: failed to add PENDING_LOCK record.\n"));
154		DLIST_REMOVE(blocking_lock_queue, blr);
155		free_blocking_lock_record(blr);
156		return False;
157	}
158
159	DLIST_ADD_END(blocking_lock_queue, blr, blocking_lock_record *);
160
161	/* Ensure we'll receive messages when this is unlocked. */
162	if (!set_lock_msg) {
163		message_register(MSG_SMB_UNLOCK, received_unlock_msg,
164				 NULL);
165		set_lock_msg = True;
166	}
167
168	DEBUG(3,("push_blocking_lock_request: lock request length=%d blocked with "
169		"expiry time (%u sec. %u usec) (+%d msec) for fnum = %d, name = %s\n",
170		length, (unsigned int)blr->expire_time.tv_sec,
171		(unsigned int)blr->expire_time.tv_usec, lock_timeout,
172		blr->fsp->fnum, blr->fsp->fsp_name ));
173
174	/* Push the MID of this packet on the signing queue. */
175	srv_defer_sign_response(SVAL(inbuf,smb_mid));
176
177	return True;
178}
179
180/****************************************************************************
181 Return a smd with a given size.
182*****************************************************************************/
183
184static void send_blocking_reply(char *outbuf, int outsize)
185{
186	if(outsize > 4)
187		smb_setlen(outbuf,outsize - 4);
188
189	if (!send_smb(smbd_server_fd(),outbuf))
190		exit_server_cleanly("send_blocking_reply: send_smb failed.");
191}
192
193/****************************************************************************
194 Return a lockingX success SMB.
195*****************************************************************************/
196
197static void reply_lockingX_success(blocking_lock_record *blr)
198{
199	char *outbuf = get_OutBuffer();
200	int bufsize = BUFFER_SIZE;
201	char *inbuf = blr->inbuf;
202	int outsize = 0;
203
204	construct_reply_common(inbuf, outbuf);
205	set_message(outbuf,2,0,True);
206
207	/*
208	 * As this message is a lockingX call we must handle
209	 * any following chained message correctly.
210	 * This is normally handled in construct_reply(),
211	 * but as that calls switch_message, we can't use
212	 * that here and must set up the chain info manually.
213	 */
214
215	outsize = chain_reply(inbuf,outbuf,blr->length,bufsize);
216
217	outsize += chain_size;
218
219	send_blocking_reply(outbuf,outsize);
220}
221
222/****************************************************************************
223 Return a generic lock fail error blocking call.
224*****************************************************************************/
225
226static void generic_blocking_lock_error(blocking_lock_record *blr, NTSTATUS status)
227{
228	char *outbuf = get_OutBuffer();
229	char *inbuf = blr->inbuf;
230	construct_reply_common(inbuf, outbuf);
231
232	/* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
233	   FILE_LOCK_CONFLICT! (tridge) */
234	if (NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
235		status = NT_STATUS_FILE_LOCK_CONFLICT;
236	}
237
238	if (NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
239		/* Store the last lock error. */
240		files_struct *fsp = blr->fsp;
241
242		fsp->last_lock_failure.context.smbpid = blr->lock_pid;
243		fsp->last_lock_failure.context.tid = fsp->conn->cnum;
244		fsp->last_lock_failure.context.pid = procid_self();
245		fsp->last_lock_failure.start = blr->offset;
246		fsp->last_lock_failure.size = blr->count;
247		fsp->last_lock_failure.fnum = fsp->fnum;
248		fsp->last_lock_failure.lock_type = READ_LOCK; /* Don't care. */
249		fsp->last_lock_failure.lock_flav = blr->lock_flav;
250	}
251
252	ERROR_NT(status);
253	if (!send_smb(smbd_server_fd(),outbuf)) {
254		exit_server_cleanly("generic_blocking_lock_error: send_smb failed.");
255	}
256}
257
258/****************************************************************************
259 Return a lock fail error for a lockingX call. Undo all the locks we have
260 obtained first.
261*****************************************************************************/
262
263static void reply_lockingX_error(blocking_lock_record *blr, NTSTATUS status)
264{
265	char *inbuf = blr->inbuf;
266	files_struct *fsp = blr->fsp;
267	uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
268	SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT) 0;
269	uint32 lock_pid;
270	unsigned char locktype = CVAL(inbuf,smb_vwv3);
271	BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
272	char *data;
273	int i;
274
275	data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
276
277	/*
278	 * Data now points at the beginning of the list
279	 * of smb_lkrng structs.
280	 */
281
282	/*
283	 * Ensure we don't do a remove on the lock that just failed,
284	 * as under POSIX rules, if we have a lock already there, we
285	 * will delete it (and we shouldn't) .....
286	 */
287
288	for(i = blr->lock_num - 1; i >= 0; i--) {
289		BOOL err;
290
291		lock_pid = get_lock_pid( data, i, large_file_format);
292		count = get_lock_count( data, i, large_file_format);
293		offset = get_lock_offset( data, i, large_file_format, &err);
294
295		/*
296		 * We know err cannot be set as if it was the lock
297		 * request would never have been queued. JRA.
298		 */
299
300		do_unlock(fsp,
301			lock_pid,
302			count,
303			offset,
304			WINDOWS_LOCK);
305	}
306
307	generic_blocking_lock_error(blr, status);
308}
309
310/****************************************************************************
311 Return a lock fail error.
312*****************************************************************************/
313
314static void blocking_lock_reply_error(blocking_lock_record *blr, NTSTATUS status)
315{
316	switch(blr->com_type) {
317	case SMBlockingX:
318		reply_lockingX_error(blr, status);
319		break;
320	case SMBtrans2:
321	case SMBtranss2:
322		{
323			char *outbuf = get_OutBuffer();
324			char *inbuf = blr->inbuf;
325			construct_reply_common(inbuf, outbuf);
326			/* construct_reply_common has done us the favor to pre-fill the
327			 * command field with SMBtranss2 which is wrong :-)
328			 */
329			SCVAL(outbuf,smb_com,SMBtrans2);
330			ERROR_NT(status);
331			if (!send_smb(smbd_server_fd(),outbuf)) {
332				exit_server_cleanly("blocking_lock_reply_error: send_smb failed.");
333			}
334			break;
335		}
336	default:
337		DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
338		exit_server("PANIC - unknown type on blocking lock queue");
339	}
340}
341
342/****************************************************************************
343 Attempt to finish off getting all pending blocking locks for a lockingX call.
344 Returns True if we want to be removed from the list.
345*****************************************************************************/
346
347static BOOL process_lockingX(blocking_lock_record *blr)
348{
349	char *inbuf = blr->inbuf;
350	unsigned char locktype = CVAL(inbuf,smb_vwv3);
351	files_struct *fsp = blr->fsp;
352	uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
353	uint16 num_locks = SVAL(inbuf,smb_vwv7);
354	SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
355	uint32 lock_pid;
356	BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
357	char *data;
358	NTSTATUS status = NT_STATUS_OK;
359
360	data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
361
362	/*
363	 * Data now points at the beginning of the list
364	 * of smb_lkrng structs.
365	 */
366
367	for(; blr->lock_num < num_locks; blr->lock_num++) {
368		struct byte_range_lock *br_lck = NULL;
369		BOOL err;
370
371		lock_pid = get_lock_pid( data, blr->lock_num, large_file_format);
372		count = get_lock_count( data, blr->lock_num, large_file_format);
373		offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
374
375		/*
376		 * We know err cannot be set as if it was the lock
377		 * request would never have been queued. JRA.
378		 */
379		errno = 0;
380		br_lck = do_lock(fsp,
381				lock_pid,
382				count,
383				offset,
384				((locktype & LOCKING_ANDX_SHARED_LOCK) ?
385					READ_LOCK : WRITE_LOCK),
386				WINDOWS_LOCK,
387				True,
388				&status,
389				&blr->blocking_pid);
390
391		TALLOC_FREE(br_lck);
392
393		if (NT_STATUS_IS_ERR(status)) {
394			break;
395		}
396	}
397
398	if(blr->lock_num == num_locks) {
399		/*
400		 * Success - we got all the locks.
401		 */
402
403		DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
404			 fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
405
406		reply_lockingX_success(blr);
407		return True;
408	} else if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
409			!NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
410			/*
411			 * We have other than a "can't get lock"
412			 * error. Free any locks we had and return an error.
413			 * Return True so we get dequeued.
414			 */
415
416		blocking_lock_reply_error(blr, status);
417		return True;
418	}
419
420	/*
421	 * Still can't get all the locks - keep waiting.
422	 */
423
424	DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
425Waiting....\n",
426		  blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
427
428	return False;
429}
430
431/****************************************************************************
432 Attempt to get the posix lock request from a SMBtrans2 call.
433 Returns True if we want to be removed from the list.
434*****************************************************************************/
435
436static BOOL process_trans2(blocking_lock_record *blr)
437{
438	char *inbuf = blr->inbuf;
439	char *outbuf;
440	char params[2];
441	NTSTATUS status;
442	struct byte_range_lock *br_lck = do_lock(blr->fsp,
443						blr->lock_pid,
444						blr->count,
445						blr->offset,
446						blr->lock_type,
447						blr->lock_flav,
448						True,
449						&status,
450						&blr->blocking_pid);
451	TALLOC_FREE(br_lck);
452
453	if (!NT_STATUS_IS_OK(status)) {
454		if (ERROR_WAS_LOCK_DENIED(status)) {
455			/* Still can't get the lock, just keep waiting. */
456			return False;
457		}
458		/*
459		 * We have other than a "can't get lock"
460		 * error. Send an error and return True so we get dequeued.
461		 */
462		blocking_lock_reply_error(blr, status);
463		return True;
464	}
465
466	/* We finally got the lock, return success. */
467	outbuf = get_OutBuffer();
468	construct_reply_common(inbuf, outbuf);
469	SCVAL(outbuf,smb_com,SMBtrans2);
470	SSVAL(params,0,0);
471	/* Fake up max_data_bytes here - we know it fits. */
472	send_trans2_replies(outbuf, max_send, params, 2, NULL, 0, 0xffff);
473	return True;
474}
475
476
477/****************************************************************************
478 Process a blocking lock SMB.
479 Returns True if we want to be removed from the list.
480*****************************************************************************/
481
482static BOOL blocking_lock_record_process(blocking_lock_record *blr)
483{
484	switch(blr->com_type) {
485		case SMBlockingX:
486			return process_lockingX(blr);
487		case SMBtrans2:
488		case SMBtranss2:
489			return process_trans2(blr);
490		default:
491			DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
492			exit_server("PANIC - unknown type on blocking lock queue");
493	}
494	return False; /* Keep compiler happy. */
495}
496
497/****************************************************************************
498 Cancel entries by fnum from the blocking lock pending queue.
499*****************************************************************************/
500
501void cancel_pending_lock_requests_by_fid(files_struct *fsp, struct byte_range_lock *br_lck)
502{
503	blocking_lock_record *blr, *next = NULL;
504
505	for(blr = blocking_lock_queue; blr; blr = next) {
506		next = blr->next;
507		if(blr->fsp->fnum == fsp->fnum) {
508			unsigned char locktype = 0;
509
510			if (blr->com_type == SMBlockingX) {
511				locktype = CVAL(blr->inbuf,smb_vwv3);
512			}
513
514			if (br_lck) {
515				DEBUG(10,("remove_pending_lock_requests_by_fid - removing request type %d for \
516file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
517
518				brl_lock_cancel(br_lck,
519					blr->lock_pid,
520					procid_self(),
521					blr->offset,
522					blr->count,
523					blr->lock_flav);
524
525				blocking_lock_cancel(fsp,
526					blr->lock_pid,
527					blr->offset,
528					blr->count,
529					blr->lock_flav,
530					locktype,
531					NT_STATUS_RANGE_NOT_LOCKED);
532			}
533		}
534	}
535}
536
537/****************************************************************************
538 Delete entries by mid from the blocking lock pending queue. Always send reply.
539*****************************************************************************/
540
541void remove_pending_lock_requests_by_mid(int mid)
542{
543	blocking_lock_record *blr, *next = NULL;
544
545	for(blr = blocking_lock_queue; blr; blr = next) {
546		next = blr->next;
547		if(SVAL(blr->inbuf,smb_mid) == mid) {
548			files_struct *fsp = blr->fsp;
549			struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
550
551			if (br_lck) {
552				DEBUG(10,("remove_pending_lock_requests_by_mid - removing request type %d for \
553file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
554
555				brl_lock_cancel(br_lck,
556					blr->lock_pid,
557					procid_self(),
558					blr->offset,
559					blr->count,
560					blr->lock_flav);
561				TALLOC_FREE(br_lck);
562			}
563
564			blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
565			DLIST_REMOVE(blocking_lock_queue, blr);
566			free_blocking_lock_record(blr);
567		}
568	}
569}
570
571/****************************************************************************
572 Is this mid a blocking lock request on the queue ?
573*****************************************************************************/
574
575BOOL blocking_lock_was_deferred(int mid)
576{
577	blocking_lock_record *blr, *next = NULL;
578
579	for(blr = blocking_lock_queue; blr; blr = next) {
580		next = blr->next;
581		if(SVAL(blr->inbuf,smb_mid) == mid) {
582			return True;
583		}
584	}
585	return False;
586}
587
588/****************************************************************************
589  Set a flag as an unlock request affects one of our pending locks.
590*****************************************************************************/
591
592static void received_unlock_msg(int msg_type, struct process_id src,
593				void *buf, size_t len,
594				void *private_data)
595{
596	DEBUG(10,("received_unlock_msg\n"));
597	process_blocking_lock_queue();
598}
599
600/****************************************************************************
601 Return the number of milliseconds to the next blocking locks timeout, or default_timeout
602*****************************************************************************/
603
604unsigned int blocking_locks_timeout_ms(unsigned int default_timeout_ms)
605{
606	unsigned int timeout_ms = default_timeout_ms;
607	struct timeval tv_curr;
608	SMB_BIG_INT min_tv_dif_us = default_timeout_ms * 1000;
609	blocking_lock_record *blr = blocking_lock_queue;
610
611	/* note that we avoid the GetTimeOfDay() syscall if there are no blocking locks */
612	if (!blr) {
613		return timeout_ms;
614	}
615
616	tv_curr = timeval_current();
617
618	for (; blr; blr = blr->next) {
619		SMB_BIG_INT tv_dif_us;
620
621		if (timeval_is_zero(&blr->expire_time)) {
622			/*
623			 * If we're blocked on pid 0xFFFFFFFF this is
624			 * a POSIX lock, so calculate a timeout of
625			 * 10 seconds.
626			 */
627			if (blr->blocking_pid == 0xFFFFFFFF) {
628				tv_dif_us = 10 * 1000 * 1000;
629				min_tv_dif_us = MIN(min_tv_dif_us, tv_dif_us);
630			}
631			continue; /* Never timeout. */
632		}
633
634		tv_dif_us = usec_time_diff(&blr->expire_time, &tv_curr);
635		min_tv_dif_us = MIN(min_tv_dif_us, tv_dif_us);
636	}
637
638	if (min_tv_dif_us < 0) {
639		min_tv_dif_us = 0;
640	}
641
642	timeout_ms = (unsigned int)(min_tv_dif_us / (SMB_BIG_INT)1000);
643
644	if (timeout_ms < 1) {
645		timeout_ms = 1;
646	}
647
648	DEBUG(10,("blocking_locks_timeout_ms: returning %u\n", timeout_ms));
649
650	return timeout_ms;
651}
652
653/****************************************************************************
654 Process the blocking lock queue. Note that this is only called as root.
655*****************************************************************************/
656
657void process_blocking_lock_queue(void)
658{
659	struct timeval tv_curr = timeval_current();
660	blocking_lock_record *blr, *next = NULL;
661
662	/*
663	 * Go through the queue and see if we can get any of the locks.
664	 */
665
666	for (blr = blocking_lock_queue; blr; blr = next) {
667		connection_struct *conn = NULL;
668		uint16 vuid;
669		files_struct *fsp = NULL;
670
671		next = blr->next;
672
673		/*
674		 * Ensure we don't have any old chain_fsp values
675		 * sitting around....
676		 */
677		chain_size = 0;
678		file_chain_reset();
679		fsp = blr->fsp;
680
681		conn = conn_find(SVAL(blr->inbuf,smb_tid));
682		vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
683				SVAL(blr->inbuf,smb_uid);
684
685		DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
686			fsp->fnum, fsp->fsp_name ));
687
688		if (!timeval_is_zero(&blr->expire_time) && timeval_compare(&blr->expire_time, &tv_curr) <= 0) {
689			struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
690
691			/*
692			 * Lock expired - throw away all previously
693			 * obtained locks and return lock error.
694			 */
695
696			if (br_lck) {
697				DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
698					fsp->fnum, fsp->fsp_name ));
699
700				brl_lock_cancel(br_lck,
701					blr->lock_pid,
702					procid_self(),
703					blr->offset,
704					blr->count,
705					blr->lock_flav);
706				TALLOC_FREE(br_lck);
707			}
708
709			blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
710			DLIST_REMOVE(blocking_lock_queue, blr);
711			free_blocking_lock_record(blr);
712			continue;
713		}
714
715		if(!change_to_user(conn,vuid)) {
716			struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
717
718			/*
719			 * Remove the entry and return an error to the client.
720			 */
721
722			if (br_lck) {
723				brl_lock_cancel(br_lck,
724					blr->lock_pid,
725					procid_self(),
726					blr->offset,
727					blr->count,
728					blr->lock_flav);
729				TALLOC_FREE(br_lck);
730			}
731
732			DEBUG(0,("process_blocking_lock_queue: Unable to become user vuid=%d.\n",
733				vuid ));
734			blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
735			DLIST_REMOVE(blocking_lock_queue, blr);
736			free_blocking_lock_record(blr);
737			continue;
738		}
739
740		if(!set_current_service(conn,SVAL(blr->inbuf,smb_flg),True)) {
741			struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
742
743			/*
744			 * Remove the entry and return an error to the client.
745			 */
746
747			if (br_lck) {
748				brl_lock_cancel(br_lck,
749					blr->lock_pid,
750					procid_self(),
751					blr->offset,
752					blr->count,
753					blr->lock_flav);
754				TALLOC_FREE(br_lck);
755			}
756
757			DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
758			blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
759			DLIST_REMOVE(blocking_lock_queue, blr);
760			free_blocking_lock_record(blr);
761			change_to_root_user();
762			continue;
763		}
764
765		/*
766		 * Go through the remaining locks and try and obtain them.
767		 * The call returns True if all locks were obtained successfully
768		 * and False if we still need to wait.
769		 */
770
771		if(blocking_lock_record_process(blr)) {
772			struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
773
774			if (br_lck) {
775				brl_lock_cancel(br_lck,
776					blr->lock_pid,
777					procid_self(),
778					blr->offset,
779					blr->count,
780					blr->lock_flav);
781				TALLOC_FREE(br_lck);
782			}
783
784			DLIST_REMOVE(blocking_lock_queue, blr);
785			free_blocking_lock_record(blr);
786		}
787		change_to_root_user();
788	}
789}
790
791/****************************************************************************
792 Handle a cancel message. Lock already moved onto the cancel queue.
793*****************************************************************************/
794
795#define MSG_BLOCKING_LOCK_CANCEL_SIZE (sizeof(blocking_lock_record *) + sizeof(NTSTATUS))
796
797static void process_blocking_lock_cancel_message(int msg_type,
798						 struct process_id src,
799						 void *buf, size_t len,
800						 void *private_data)
801{
802	NTSTATUS err;
803	const char *msg = (const char *)buf;
804	blocking_lock_record *blr;
805
806	if (buf == NULL) {
807		smb_panic("process_blocking_lock_cancel_message: null msg\n");
808	}
809
810	if (len != MSG_BLOCKING_LOCK_CANCEL_SIZE) {
811		DEBUG(0, ("process_blocking_lock_cancel_message: "
812			"Got invalid msg len %d\n", (int)len));
813		smb_panic("process_blocking_lock_cancel_message: bad msg\n");
814        }
815
816	memcpy(&blr, msg, sizeof(blr));
817	memcpy(&err, &msg[sizeof(blr)], sizeof(NTSTATUS));
818
819	DEBUG(10,("process_blocking_lock_cancel_message: returning error %s\n",
820		nt_errstr(err) ));
821
822	blocking_lock_reply_error(blr, err);
823	DLIST_REMOVE(blocking_lock_cancelled_queue, blr);
824	free_blocking_lock_record(blr);
825}
826
827/****************************************************************************
828 Send ourselves a blocking lock cancelled message. Handled asynchronously above.
829*****************************************************************************/
830
831BOOL blocking_lock_cancel(files_struct *fsp,
832			uint32 lock_pid,
833			SMB_BIG_UINT offset,
834			SMB_BIG_UINT count,
835			enum brl_flavour lock_flav,
836			unsigned char locktype,
837                        NTSTATUS err)
838{
839	static BOOL initialized;
840	char msg[MSG_BLOCKING_LOCK_CANCEL_SIZE];
841	blocking_lock_record *blr;
842
843	if (!initialized) {
844		/* Register our message. */
845		message_register(MSG_SMB_BLOCKING_LOCK_CANCEL,
846				 process_blocking_lock_cancel_message,
847				 NULL);
848
849		initialized = True;
850	}
851
852	for (blr = blocking_lock_queue; blr; blr = blr->next) {
853		if (fsp == blr->fsp &&
854				lock_pid == blr->lock_pid &&
855				offset == blr->offset &&
856				count == blr->count &&
857				lock_flav == blr->lock_flav) {
858			break;
859		}
860	}
861
862	if (!blr) {
863		return False;
864	}
865
866	/* Check the flags are right. */
867	if (blr->com_type == SMBlockingX &&
868		(locktype & LOCKING_ANDX_LARGE_FILES) !=
869			(CVAL(blr->inbuf,smb_vwv3) & LOCKING_ANDX_LARGE_FILES)) {
870		return False;
871	}
872
873	/* Move to cancelled queue. */
874	DLIST_REMOVE(blocking_lock_queue, blr);
875	DLIST_ADD(blocking_lock_cancelled_queue, blr);
876
877	/* Create the message. */
878	memcpy(msg, &blr, sizeof(blr));
879	memcpy(&msg[sizeof(blr)], &err, sizeof(NTSTATUS));
880
881	message_send_pid(pid_to_procid(sys_getpid()),
882			MSG_SMB_BLOCKING_LOCK_CANCEL,
883			&msg, sizeof(msg), True);
884
885	return True;
886}
887