2 Unix SMB/Netbios implementation.
4 Blocking Locking functions
5 Copyright (C) Jeremy Allison 1998
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 extern int DEBUGLEVEL;
24 extern char *OutBuffer;
26 /****************************************************************************
27 This is the structure to queue to implement blocking locks.
28 notify. It consists of the requesting SMB and the expiry time.
29 *****************************************************************************/
39 } blocking_lock_record;
41 static ubi_slList blocking_lock_queue = { NULL, (ubi_slNodePtr)&blocking_lock_queue, 0};
43 /****************************************************************************
44 Destructor for the above structure.
45 ****************************************************************************/
47 static void free_blocking_lock_record(blocking_lock_record *blr)
53 /****************************************************************************
54 Get the files_struct given a particular queued SMB.
55 *****************************************************************************/
57 static files_struct *get_fsp_from_pkt(char *inbuf)
59 switch(CVAL(inbuf,smb_com)) {
62 return file_fsp(inbuf,smb_vwv0);
64 return file_fsp(inbuf,smb_vwv2);
66 DEBUG(0,("get_fsp_from_pkt: PANIC - unknown type on blocking lock queue - exiting.!\n"));
67 exit_server("PANIC - unknown type on blocking lock queue");
69 return NULL; /* Keep compiler happy. */
72 /****************************************************************************
73 Determine if this is a secondary element of a chained SMB.
74 **************************************************************************/
76 static BOOL in_chained_smb(void)
78 return (chain_size != 0);
81 /****************************************************************************
82 Function to push a blocking lock request onto the lock queue.
83 ****************************************************************************/
85 BOOL push_blocking_lock_request( char *inbuf, int length, int lock_timeout, int lock_num)
87 blocking_lock_record *blr;
89 if(in_chained_smb() ) {
90 DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
95 * Now queue an entry on the blocking lock queue. We setup
96 * the expiration time here.
99 if((blr = (blocking_lock_record *)malloc(sizeof(blocking_lock_record))) == NULL) {
100 DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
104 if((blr->inbuf = (char *)malloc(length)) == NULL) {
105 DEBUG(0,("push_blocking_lock_request: Malloc fail (2)!\n" ));
110 blr->com_type = CVAL(inbuf,smb_com);
111 blr->fsp = get_fsp_from_pkt(inbuf);
112 blr->expire_time = (lock_timeout == -1) ? (time_t)-1 : time(NULL) + (time_t)lock_timeout;
113 blr->lock_num = lock_num;
114 memcpy(blr->inbuf, inbuf, length);
115 blr->length = length;
117 ubi_slAddTail(&blocking_lock_queue, blr);
120 DEBUG(3,("push_blocking_lock_request: lock request length=%d blocked with expiry time %d (+%d) \
121 for fnum = %d, name = %s\n", length, (int)blr->expire_time, lock_timeout,
122 blr->fsp->fnum, blr->fsp->fsp_name ));
127 /****************************************************************************
128 Return a smd with a given size.
129 *****************************************************************************/
131 static void send_blocking_reply(char *outbuf, int outsize)
134 smb_setlen(outbuf,outsize - 4);
136 send_smb(smbd_server_fd(),outbuf);
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, int eclass, int32 ecode)
174 char *outbuf = OutBuffer;
175 char *inbuf = blr->inbuf;
176 construct_reply_common(inbuf, outbuf);
178 if(eclass == 0) /* NT Error. */
179 SSVAL(outbuf,smb_flg2, SVAL(outbuf,smb_flg2) | FLAGS2_32_BIT_ERROR_CODES);
182 send_smb(smbd_server_fd(),outbuf);
185 /****************************************************************************
186 Return a lock fail error for a lockingX call. Undo all the locks we have
188 *****************************************************************************/
190 static void reply_lockingX_error(blocking_lock_record *blr, int eclass, int32 ecode)
192 char *inbuf = blr->inbuf;
193 files_struct *fsp = blr->fsp;
194 connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
195 uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
196 SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT) 0;
197 unsigned char locktype = CVAL(inbuf,smb_vwv3);
198 BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
202 data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
205 * Data now points at the beginning of the list
206 * of smb_lkrng structs.
210 * Ensure we don't do a remove on the lock that just failed,
211 * as under POSIX rules, if we have a lock already there, we
212 * will delete it (and we shouldn't) .....
215 for(i = blr->lock_num - 1; i >= 0; i--) {
220 count = get_lock_count( data, i, large_file_format);
221 offset = get_lock_offset( data, i, large_file_format, &err);
224 * We know err cannot be set as if it was the lock
225 * request would never have been queued. JRA.
228 do_unlock(fsp,conn,count,offset,&dummy1,&dummy2);
231 generic_blocking_lock_error(blr, eclass, ecode);
234 /****************************************************************************
235 Return a lock fail error.
236 *****************************************************************************/
238 static void blocking_lock_reply_error(blocking_lock_record *blr, int eclass, int32 ecode)
240 switch(blr->com_type) {
242 generic_blocking_lock_error(blr, eclass, ecode);
245 generic_blocking_lock_error(blr, eclass, ecode);
248 reply_lockingX_error(blr, eclass, ecode);
251 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
252 exit_server("PANIC - unknown type on blocking lock queue");
256 /****************************************************************************
257 Attempt to finish off getting all pending blocking locks for a lockread call.
258 Returns True if we want to be removed from the list.
259 *****************************************************************************/
261 static BOOL process_lockread(blocking_lock_record *blr)
263 char *outbuf = OutBuffer;
264 char *inbuf = blr->inbuf;
272 connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
273 files_struct *fsp = blr->fsp;
275 numtoread = SVAL(inbuf,smb_vwv1);
276 startpos = IVAL(inbuf,smb_vwv2);
278 numtoread = MIN(BUFFER_SIZE-outsize,numtoread);
279 data = smb_buf(outbuf) + 3;
281 if(!do_lock( fsp, conn, (SMB_BIG_UINT)numtoread, (SMB_BIG_UINT)startpos, READ_LOCK, &eclass, &ecode)) {
282 if((errno != EACCES) && (errno != EAGAIN)) {
284 * We have other than a "can't get lock" POSIX
285 * error. Send an error.
286 * Return True so we get dequeued.
289 generic_blocking_lock_error(blr, eclass, ecode);
294 * Still waiting for lock....
297 DEBUG(10,("process_lockread: failed to get lock for file = %s. Still waiting....\n",
302 nread = read_file(fsp,data,startpos,numtoread);
305 generic_blocking_lock_error(blr,ERRDOS,ERRnoaccess);
309 construct_reply_common(inbuf, outbuf);
310 outsize = set_message(outbuf,5,3,True);
313 SSVAL(outbuf,smb_vwv0,nread);
314 SSVAL(outbuf,smb_vwv5,nread+3);
315 SSVAL(smb_buf(outbuf),1,nread);
317 DEBUG(3, ( "process_lockread file = %s, fnum=%d num=%d nread=%d\n",
318 fsp->fsp_name, fsp->fnum, (int)numtoread, (int)nread ) );
320 send_blocking_reply(outbuf,outsize);
324 /****************************************************************************
325 Attempt to finish off getting all pending blocking locks for a lock call.
326 Returns True if we want to be removed from the list.
327 *****************************************************************************/
329 static BOOL process_lock(blocking_lock_record *blr)
331 char *outbuf = OutBuffer;
332 char *inbuf = blr->inbuf;
334 SMB_OFF_T count = 0, offset = 0;
337 connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
338 files_struct *fsp = blr->fsp;
340 count = IVAL(inbuf,smb_vwv1);
341 offset = IVAL(inbuf,smb_vwv3);
344 if (!do_lock(fsp, conn, (SMB_BIG_UINT)count, (SMB_BIG_UINT)offset, WRITE_LOCK, &eclass, &ecode)) {
345 if((errno != EACCES) && (errno != EAGAIN)) {
348 * We have other than a "can't get lock" POSIX
349 * error. Send an error.
350 * Return True so we get dequeued.
353 blocking_lock_reply_error(blr, eclass, ecode);
358 * Still can't get the lock - keep waiting.
361 DEBUG(10,("process_lock: failed to get lock for file = %s. Still waiting....\n",
367 * Success - we got the lock.
370 DEBUG(3,("process_lock : file=%s fnum=%d offset=%.0f count=%.0f\n",
371 fsp->fsp_name, fsp->fnum, (double)offset, (double)count));
373 construct_reply_common(inbuf, outbuf);
374 outsize = set_message(outbuf,0,0,True);
375 send_blocking_reply(outbuf,outsize);
379 /****************************************************************************
380 Attempt to finish off getting all pending blocking locks for a lockingX call.
381 Returns True if we want to be removed from the list.
382 *****************************************************************************/
384 static BOOL process_lockingX(blocking_lock_record *blr)
386 char *inbuf = blr->inbuf;
387 unsigned char locktype = CVAL(inbuf,smb_vwv3);
388 files_struct *fsp = blr->fsp;
389 connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
390 uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
391 uint16 num_locks = SVAL(inbuf,smb_vwv7);
392 SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
393 BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
398 data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
401 * Data now points at the beginning of the list
402 * of smb_lkrng structs.
405 for(; blr->lock_num < num_locks; blr->lock_num++) {
408 count = get_lock_count( data, blr->lock_num, large_file_format);
409 offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
412 * We know err cannot be set as if it was the lock
413 * request would never have been queued. JRA.
416 if(!do_lock(fsp,conn,count,offset, ((locktype & 1) ? READ_LOCK : WRITE_LOCK),
421 if(blr->lock_num == num_locks) {
424 * Success - we got all the locks.
427 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
428 fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
430 reply_lockingX_success(blr);
433 } else if((errno != EACCES) && (errno != EAGAIN)) {
436 * We have other than a "can't get lock" POSIX
437 * error. Free any locks we had and return an error.
438 * Return True so we get dequeued.
441 blocking_lock_reply_error(blr, eclass, ecode);
446 * Still can't get all the locks - keep waiting.
449 DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
450 Waiting....\n", blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
455 /****************************************************************************
456 Process a blocking lock SMB.
457 Returns True if we want to be removed from the list.
458 *****************************************************************************/
460 static BOOL blocking_lock_record_process(blocking_lock_record *blr)
462 switch(blr->com_type) {
464 return process_lock(blr);
466 return process_lockread(blr);
468 return process_lockingX(blr);
470 DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
471 exit_server("PANIC - unknown type on blocking lock queue");
473 return False; /* Keep compiler happy. */
476 /****************************************************************************
477 Delete entries by fnum from the blocking lock pending queue.
478 *****************************************************************************/
480 void remove_pending_lock_requests_by_fid(files_struct *fsp)
482 blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
483 blocking_lock_record *prev = NULL;
486 if(blr->fsp->fnum == fsp->fnum) {
488 DEBUG(10,("remove_pending_lock_requests_by_fid - removing request type %d for \
489 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
491 free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
492 blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
497 blr = (blocking_lock_record *)ubi_slNext(blr);
501 /****************************************************************************
502 Delete entries by mid from the blocking lock pending queue. Always send reply.
503 *****************************************************************************/
505 void remove_pending_lock_requests_by_mid(int mid)
507 blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
508 blocking_lock_record *prev = NULL;
511 if(SVAL(blr->inbuf,smb_mid) == mid) {
512 files_struct *fsp = blr->fsp;
514 DEBUG(10,("remove_pending_lock_requests_by_mid - removing request type %d for \
515 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
517 blocking_lock_reply_error(blr,0,NT_STATUS_CANCELLED);
518 free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
519 blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
524 blr = (blocking_lock_record *)ubi_slNext(blr);
528 /****************************************************************************
529 Return True if the blocking lock queue has entries.
530 *****************************************************************************/
532 BOOL blocking_locks_pending(void)
534 blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
535 return (blr == NULL ? False : True);
538 /****************************************************************************
539 Process the blocking lock queue. Note that this is only called as root.
540 *****************************************************************************/
542 void process_blocking_lock_queue(time_t t)
544 blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
545 blocking_lock_record *prev = NULL;
551 * Go through the queue and see if we can get any of the locks.
555 connection_struct *conn = NULL;
557 files_struct *fsp = NULL;
560 * Ensure we don't have any old chain_fsp values
567 conn = conn_find(SVAL(blr->inbuf,smb_tid));
568 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
569 SVAL(blr->inbuf,smb_uid);
571 DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
572 fsp->fnum, fsp->fsp_name ));
574 if((blr->expire_time != -1) && (blr->expire_time > t)) {
576 * Lock expired - throw away all previously
577 * obtained locks and return lock error.
579 DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
580 fsp->fnum, fsp->fsp_name ));
582 blocking_lock_reply_error(blr,ERRSRV,ERRaccess);
583 free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
584 blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
588 if(!become_user(conn,vuid)) {
589 DEBUG(0,("process_blocking_lock_queue: Unable to become user vuid=%d.\n",
592 * Remove the entry and return an error to the client.
594 blocking_lock_reply_error(blr,ERRSRV,ERRaccess);
595 free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
596 blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
600 if(!become_service(conn,True)) {
601 DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
603 * Remove the entry and return an error to the client.
605 blocking_lock_reply_error(blr,ERRSRV,ERRaccess);
606 free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
607 blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
613 * Go through the remaining locks and try and obtain them.
614 * The call returns True if all locks were obtained successfully
615 * and False if we still need to wait.
618 if(blocking_lock_record_process(blr)) {
619 free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
620 blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
628 * Move to the next in the list.
631 blr = (blocking_lock_record *)ubi_slNext(blr);