2 Unix SMB/CIFS implementation.
3 Blocking Locking functions
4 Copyright (C) Jeremy Allison 1998
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.
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.
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.
23 extern char *OutBuffer;
25 /****************************************************************************
26 This is the structure to queue to implement blocking locks.
27 notify. It consists of the requesting SMB and the expiry time.
28 *****************************************************************************/
38 } blocking_lock_record;
40 static ubi_slList blocking_lock_queue = { NULL, (ubi_slNodePtr)&blocking_lock_queue, 0};
42 /****************************************************************************
43 Destructor for the above structure.
44 ****************************************************************************/
46 static void free_blocking_lock_record(blocking_lock_record *blr)
48 SAFE_FREE(blr->inbuf);
52 /****************************************************************************
53 Get the files_struct given a particular queued SMB.
54 *****************************************************************************/
56 static files_struct *get_fsp_from_pkt(char *inbuf)
58 switch(CVAL(inbuf,smb_com)) {
61 return file_fsp(inbuf,smb_vwv0);
63 return file_fsp(inbuf,smb_vwv2);
65 DEBUG(0,("get_fsp_from_pkt: PANIC - unknown type on blocking lock queue - exiting.!\n"));
66 exit_server("PANIC - unknown type on blocking lock queue");
68 return NULL; /* Keep compiler happy. */
71 /****************************************************************************
72 Determine if this is a secondary element of a chained SMB.
73 **************************************************************************/
75 static BOOL in_chained_smb(void)
77 return (chain_size != 0);
80 /****************************************************************************
81 Function to push a blocking lock request onto the lock queue.
82 ****************************************************************************/
84 BOOL push_blocking_lock_request( char *inbuf, int length, int lock_timeout, int lock_num)
86 blocking_lock_record *blr;
88 if(in_chained_smb() ) {
89 DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
94 * Now queue an entry on the blocking lock queue. We setup
95 * the expiration time here.
98 if((blr = (blocking_lock_record *)malloc(sizeof(blocking_lock_record))) == NULL) {
99 DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
103 if((blr->inbuf = (char *)malloc(length)) == NULL) {
104 DEBUG(0,("push_blocking_lock_request: Malloc fail (2)!\n" ));
109 blr->com_type = CVAL(inbuf,smb_com);
110 blr->fsp = get_fsp_from_pkt(inbuf);
111 blr->expire_time = (lock_timeout == -1) ? (time_t)-1 : time(NULL) + (time_t)lock_timeout;
112 blr->lock_num = lock_num;
113 memcpy(blr->inbuf, inbuf, length);
114 blr->length = length;
116 ubi_slAddTail(&blocking_lock_queue, blr);
119 DEBUG(3,("push_blocking_lock_request: lock request length=%d blocked with expiry time %d (+%d) \
120 for fnum = %d, name = %s\n", length, (int)blr->expire_time, lock_timeout,
121 blr->fsp->fnum, blr->fsp->fsp_name ));
126 /****************************************************************************
127 Return a smd with a given size.
128 *****************************************************************************/
130 static void send_blocking_reply(char *outbuf, int outsize)
133 smb_setlen(outbuf,outsize - 4);
135 if (!send_smb(smbd_server_fd(),outbuf))
136 exit_server("send_blocking_reply: send_smb failed.");
139 /****************************************************************************
140 Return a lockingX success SMB.
141 *****************************************************************************/
143 static void reply_lockingX_success(blocking_lock_record *blr)
145 char *outbuf = OutBuffer;
146 int bufsize = BUFFER_SIZE;
147 char *inbuf = blr->inbuf;
150 construct_reply_common(inbuf, outbuf);
151 set_message(outbuf,2,0,True);
154 * As this message is a lockingX call we must handle
155 * any following chained message correctly.
156 * This is normally handled in construct_reply(),
157 * but as that calls switch_message, we can't use
158 * that here and must set up the chain info manually.
161 outsize = chain_reply(inbuf,outbuf,blr->length,bufsize);
163 outsize += chain_size;
165 send_blocking_reply(outbuf,outsize);
168 /****************************************************************************
169 Return a generic lock fail error blocking call.
170 *****************************************************************************/
172 static void generic_blocking_lock_error(blocking_lock_record *blr, NTSTATUS status)
174 char *outbuf = OutBuffer;
175 char *inbuf = blr->inbuf;
176 construct_reply_common(inbuf, outbuf);
179 if (!send_smb(smbd_server_fd(),outbuf))
180 exit_server("generic_blocking_lock_error: send_smb failed.");
183 /****************************************************************************
184 Return a lock fail error for a lockingX call. Undo all the locks we have
186 *****************************************************************************/
188 static void reply_lockingX_error(blocking_lock_record *blr, NTSTATUS status)
190 char *inbuf = blr->inbuf;
191 files_struct *fsp = blr->fsp;
192 connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
193 uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
194 SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT) 0;
196 unsigned char locktype = CVAL(inbuf,smb_vwv3);
197 BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
201 data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
204 * Data now points at the beginning of the list
205 * of smb_lkrng structs.
209 * Ensure we don't do a remove on the lock that just failed,
210 * as under POSIX rules, if we have a lock already there, we
211 * will delete it (and we shouldn't) .....
214 for(i = blr->lock_num - 1; i >= 0; i--) {
217 lock_pid = get_lock_pid( data, i, large_file_format);
218 count = get_lock_count( data, i, large_file_format);
219 offset = get_lock_offset( data, i, large_file_format, &err);
222 * We know err cannot be set as if it was the lock
223 * request would never have been queued. JRA.
226 do_unlock(fsp,conn,lock_pid,count,offset);
229 generic_blocking_lock_error(blr, status);
232 /****************************************************************************
233 Return a lock fail error.
234 *****************************************************************************/
236 static void blocking_lock_reply_error(blocking_lock_record *blr, NTSTATUS status)
238 switch(blr->com_type) {
241 generic_blocking_lock_error(blr, status);
244 reply_lockingX_error(blr, status);
247 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
248 exit_server("PANIC - unknown type on blocking lock queue");
252 /****************************************************************************
253 Attempt to finish off getting all pending blocking locks for a lockread call.
254 Returns True if we want to be removed from the list.
255 *****************************************************************************/
257 static BOOL process_lockread(blocking_lock_record *blr)
259 char *outbuf = OutBuffer;
260 char *inbuf = blr->inbuf;
267 connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
268 files_struct *fsp = blr->fsp;
270 numtoread = SVAL(inbuf,smb_vwv1);
271 startpos = IVAL(inbuf,smb_vwv2);
273 numtoread = MIN(BUFFER_SIZE-outsize,numtoread);
274 data = smb_buf(outbuf) + 3;
276 status = do_lock( fsp, conn, SVAL(inbuf,smb_pid), (SMB_BIG_UINT)numtoread,
277 (SMB_BIG_UINT)startpos, READ_LOCK);
278 if (NT_STATUS_V(status)) {
279 if ((errno != EACCES) && (errno != EAGAIN)) {
281 * We have other than a "can't get lock" POSIX
282 * error. Send an error.
283 * Return True so we get dequeued.
285 generic_blocking_lock_error(blr, status);
290 * Still waiting for lock....
293 DEBUG(10,("process_lockread: failed to get lock for file = %s. Still waiting....\n",
298 nread = read_file(fsp,data,startpos,numtoread);
301 generic_blocking_lock_error(blr,NT_STATUS_ACCESS_DENIED);
305 construct_reply_common(inbuf, outbuf);
306 outsize = set_message(outbuf,5,0,True);
309 SSVAL(outbuf,smb_vwv0,nread);
310 SSVAL(outbuf,smb_vwv5,nread+3);
313 SSVAL(p,0,nread); p += 2;
314 set_message_end(outbuf, p+nread);
316 DEBUG(3, ( "process_lockread file = %s, fnum=%d num=%d nread=%d\n",
317 fsp->fsp_name, fsp->fnum, (int)numtoread, (int)nread ) );
319 send_blocking_reply(outbuf,outsize);
323 /****************************************************************************
324 Attempt to finish off getting all pending blocking locks for a lock call.
325 Returns True if we want to be removed from the list.
326 *****************************************************************************/
328 static BOOL process_lock(blocking_lock_record *blr)
330 char *outbuf = OutBuffer;
331 char *inbuf = blr->inbuf;
333 SMB_OFF_T count = 0, offset = 0;
335 connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
336 files_struct *fsp = blr->fsp;
338 count = IVAL(inbuf,smb_vwv1);
339 offset = IVAL(inbuf,smb_vwv3);
342 status = do_lock(fsp, conn, SVAL(inbuf,smb_pid), (SMB_BIG_UINT)count,
343 (SMB_BIG_UINT)offset, WRITE_LOCK);
344 if (NT_STATUS_IS_ERR(status)) {
345 if((errno != EACCES) && (errno != EAGAIN)) {
347 * We have other than a "can't get lock" POSIX
348 * error. Send an error.
349 * Return True so we get dequeued.
352 blocking_lock_reply_error(blr, status);
356 * Still can't get the lock - keep waiting.
358 DEBUG(10,("process_lock: failed to get lock for file = %s. Still waiting....\n",
364 * Success - we got the lock.
367 DEBUG(3,("process_lock : file=%s fnum=%d offset=%.0f count=%.0f\n",
368 fsp->fsp_name, fsp->fnum, (double)offset, (double)count));
370 construct_reply_common(inbuf, outbuf);
371 outsize = set_message(outbuf,0,0,True);
372 send_blocking_reply(outbuf,outsize);
376 /****************************************************************************
377 Attempt to finish off getting all pending blocking locks for a lockingX call.
378 Returns True if we want to be removed from the list.
379 *****************************************************************************/
381 static BOOL process_lockingX(blocking_lock_record *blr)
383 char *inbuf = blr->inbuf;
384 unsigned char locktype = CVAL(inbuf,smb_vwv3);
385 files_struct *fsp = blr->fsp;
386 connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
387 uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
388 uint16 num_locks = SVAL(inbuf,smb_vwv7);
389 SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
391 BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
393 NTSTATUS status = NT_STATUS_OK;
395 data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
398 * Data now points at the beginning of the list
399 * of smb_lkrng structs.
402 for(; blr->lock_num < num_locks; blr->lock_num++) {
405 lock_pid = get_lock_pid( data, blr->lock_num, large_file_format);
406 count = get_lock_count( data, blr->lock_num, large_file_format);
407 offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
410 * We know err cannot be set as if it was the lock
411 * request would never have been queued. JRA.
414 status = do_lock(fsp,conn,lock_pid,count,offset,
415 ((locktype & 1) ? READ_LOCK : WRITE_LOCK));
416 if (NT_STATUS_IS_ERR(status)) break;
419 if(blr->lock_num == num_locks) {
421 * Success - we got all the locks.
424 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
425 fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
427 reply_lockingX_success(blr);
429 } else if ((errno != EACCES) && (errno != EAGAIN)) {
431 * We have other than a "can't get lock" POSIX
432 * error. Free any locks we had and return an error.
433 * Return True so we get dequeued.
436 blocking_lock_reply_error(blr, status);
441 * Still can't get all the locks - keep waiting.
444 DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
446 blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
451 /****************************************************************************
452 Process a blocking lock SMB.
453 Returns True if we want to be removed from the list.
454 *****************************************************************************/
456 static BOOL blocking_lock_record_process(blocking_lock_record *blr)
458 switch(blr->com_type) {
460 return process_lock(blr);
462 return process_lockread(blr);
464 return process_lockingX(blr);
466 DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
467 exit_server("PANIC - unknown type on blocking lock queue");
469 return False; /* Keep compiler happy. */
472 /****************************************************************************
473 Delete entries by fnum from the blocking lock pending queue.
474 *****************************************************************************/
476 void remove_pending_lock_requests_by_fid(files_struct *fsp)
478 blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
479 blocking_lock_record *prev = NULL;
482 if(blr->fsp->fnum == fsp->fnum) {
484 DEBUG(10,("remove_pending_lock_requests_by_fid - removing request type %d for \
485 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
487 free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
488 blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
493 blr = (blocking_lock_record *)ubi_slNext(blr);
497 /****************************************************************************
498 Delete entries by mid from the blocking lock pending queue. Always send reply.
499 *****************************************************************************/
501 void remove_pending_lock_requests_by_mid(int mid)
503 blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
504 blocking_lock_record *prev = NULL;
507 if(SVAL(blr->inbuf,smb_mid) == mid) {
508 files_struct *fsp = blr->fsp;
510 DEBUG(10,("remove_pending_lock_requests_by_mid - removing request type %d for \
511 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
513 blocking_lock_reply_error(blr,NT_STATUS_CANCELLED);
514 free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
515 blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
520 blr = (blocking_lock_record *)ubi_slNext(blr);
524 /****************************************************************************
525 Return True if the blocking lock queue has entries.
526 *****************************************************************************/
528 BOOL blocking_locks_pending(void)
530 blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
531 return (blr == NULL ? False : True);
534 /****************************************************************************
535 Process the blocking lock queue. Note that this is only called as root.
536 *****************************************************************************/
538 void process_blocking_lock_queue(time_t t)
540 blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
541 blocking_lock_record *prev = NULL;
547 * Go through the queue and see if we can get any of the locks.
551 connection_struct *conn = NULL;
553 files_struct *fsp = NULL;
556 * Ensure we don't have any old chain_fsp values
563 conn = conn_find(SVAL(blr->inbuf,smb_tid));
564 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
565 SVAL(blr->inbuf,smb_uid);
567 DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
568 fsp->fnum, fsp->fsp_name ));
570 if((blr->expire_time != -1) && (blr->expire_time > t)) {
572 * Lock expired - throw away all previously
573 * obtained locks and return lock error.
575 DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
576 fsp->fnum, fsp->fsp_name ));
578 blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
579 free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
580 blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
584 if(!change_to_user(conn,vuid)) {
585 DEBUG(0,("process_blocking_lock_queue: Unable to become user vuid=%d.\n",
588 * Remove the entry and return an error to the client.
590 blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
591 free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
592 blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
596 if(!set_current_service(conn,True)) {
597 DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
599 * Remove the entry and return an error to the client.
601 blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
602 free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
603 blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
604 change_to_root_user();
609 * Go through the remaining locks and try and obtain them.
610 * The call returns True if all locks were obtained successfully
611 * and False if we still need to wait.
614 if(blocking_lock_record_process(blr)) {
615 free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
616 blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
617 change_to_root_user();
621 change_to_root_user();
624 * Move to the next in the list.
627 blr = (blocking_lock_record *)ubi_slNext(blr);