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authorJeremy Allison <jra@samba.org>1998-08-19 01:49:57 +0000
committerJeremy Allison <jra@samba.org>1998-08-19 01:49:57 +0000
commit3f153e592b420ed79688b97559de9586a0f7b6fd (patch)
tree84aa1329db0b1903aaa91b5c83a82e2fef01eb21
parent12de4034c72ea5054d716bf848c2b16bef7a4d89 (diff)
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Blocking lock code split out...
Jeremy. (This used to be commit 9cdb148ef56dc8f74891f5c6e9cae10142bd4c6e)
-rw-r--r--source3/smbd/blocking.c375
1 files changed, 375 insertions, 0 deletions
diff --git a/source3/smbd/blocking.c b/source3/smbd/blocking.c
new file mode 100644
index 0000000000..294dafc405
--- /dev/null
+++ b/source3/smbd/blocking.c
@@ -0,0 +1,375 @@
+/*
+ Unix SMB/Netbios implementation.
+ Version 1.9.
+ Blocking Locking functions
+ Copyright (C) Jeremy Allison 1998
+
+ 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 2 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, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+extern int DEBUGLEVEL;
+extern int Client;
+
+/****************************************************************************
+ This is the structure to queue to implement blocking locks.
+ notify. It consists of the requesting SMB and the expiry time.
+*****************************************************************************/
+
+typedef struct {
+ ubi_slNode msg_next;
+ time_t expire_time;
+ int lock_num;
+ char *inbuf;
+ int length;
+} blocking_lock_record;
+
+static ubi_slList blocking_lock_queue = { NULL, (ubi_slNodePtr)&blocking_lock_queue, 0};
+
+/****************************************************************************
+ Destructor for the above structure.
+****************************************************************************/
+
+static void free_blocking_lock_record(blocking_lock_record *blr)
+{
+ free(blr->inbuf);
+ free((char *)blr);
+}
+
+/****************************************************************************
+ Function to push a blocking lockingX request onto the lock queue.
+ NB. We can only get away with this as the CIFS spec only includes
+ SMB_COM_LOCKING_ANDX as a head SMB, ie. it is not one that is ever
+ generated as part of a chain.
+****************************************************************************/
+
+BOOL push_blocking_lock_request( char *inbuf, int length, int lock_timeout, int lock_num)
+{
+ blocking_lock_record *blr;
+ files_struct *fsp = file_fsp(inbuf,smb_vwv2);
+
+ /*
+ * Now queue an entry on the blocking lock queue. We setup
+ * the expiration time here.
+ */
+
+ if((blr = (blocking_lock_record *)malloc(sizeof(blocking_lock_record))) == NULL) {
+ DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
+ return False;
+ }
+
+ if((blr->inbuf = (char *)malloc(length)) == NULL) {
+ DEBUG(0,("push_blocking_lock_request: Malloc fail (2)!\n" ));
+ free((char *)blr);
+ return False;
+ }
+
+ memcpy(blr->inbuf, inbuf, length);
+ blr->length = length;
+ blr->lock_num = lock_num;
+ blr->expire_time = (lock_timeout == -1) ? (time_t)-1 : time(NULL) + (time_t)lock_timeout;
+
+ ubi_slAddTail(&blocking_lock_queue, blr);
+
+ DEBUG(3,("push_blocking_lock_request: lock request blocked with expiry time %d \
+for fnum = %d, name = %s\n", (int)blr->expire_time, fsp->fnum, fsp->fsp_name ));
+
+ return True;
+}
+
+/****************************************************************************
+ Return a blocking lock success SMB.
+*****************************************************************************/
+
+static void blocking_lock_reply_success(blocking_lock_record *blr)
+{
+ extern int chain_size;
+ extern char *OutBuffer;
+ char *outbuf = OutBuffer;
+ int bufsize = BUFFER_SIZE;
+ char *inbuf = blr->inbuf;
+ int outsize = 0;
+
+ construct_reply_common(inbuf, outbuf);
+ set_message(outbuf,2,0,True);
+
+ /*
+ * As this message is a lockingX call we must handle
+ * any following chained message correctly.
+ * This is normally handled in construct_reply(),
+ * but as that calls switch_message, we can't use
+ * that here and must set up the chain info manually.
+ */
+
+ chain_size = 0;
+
+ outsize = chain_reply(inbuf,outbuf,blr->length,bufsize);
+
+ outsize += chain_size;
+
+ if(outsize > 4)
+ smb_setlen(outbuf,outsize - 4);
+
+ send_smb(Client,outbuf);
+}
+
+/****************************************************************************
+ Return a lock fail error. Undo all the locks we have obtained first.
+*****************************************************************************/
+
+static void blocking_lock_reply_error(blocking_lock_record *blr, int eclass, int32 ecode)
+{
+ extern char *OutBuffer;
+ char *outbuf = OutBuffer;
+ char *inbuf = blr->inbuf;
+ files_struct *fsp = file_fsp(inbuf,smb_vwv2);
+ connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
+ uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
+ uint32 count, offset;
+ char *data;
+ int i;
+
+ data = smb_buf(inbuf) + 10*num_ulocks;
+
+ /*
+ * Data now points at the beginning of the list
+ * of smb_lkrng structs.
+ */
+
+ for(i = blr->lock_num; i >= 0; i--) {
+ int dummy1;
+ uint32 dummy2;
+ count = IVAL(data,SMB_LKLEN_OFFSET(i));
+ offset = IVAL(data,SMB_LKOFF_OFFSET(i));
+ do_unlock(fsp,conn,count,offset,&dummy1,&dummy2);
+ }
+
+ construct_reply_common(inbuf, outbuf);
+
+ if(eclass == 0) /* NT Error. */
+ SSVAL(outbuf,smb_flg2, SVAL(outbuf,smb_flg2) | FLAGS2_32_BIT_ERROR_CODES);
+
+ ERROR(eclass,ecode);
+ send_smb(Client,outbuf);
+}
+
+/****************************************************************************
+ Attempt to finish off getting all pending blocking locks.
+ Returns True if we want to be removed from the list.
+*****************************************************************************/
+
+static BOOL blocking_lock_record_process(blocking_lock_record *blr)
+{
+ char *inbuf = blr->inbuf;
+ unsigned char locktype = CVAL(inbuf,smb_vwv3);
+ files_struct *fsp = file_fsp(inbuf,smb_vwv2);
+ connection_struct *conn = conn_find(SVAL(inbuf,smb_tid));
+ uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
+ uint16 num_locks = SVAL(inbuf,smb_vwv7);
+ uint32 count, offset;
+ char *data;
+ int eclass=0;
+ uint32 ecode=0;
+
+ data = smb_buf(inbuf) + 10*num_ulocks;
+
+ /*
+ * Data now points at the beginning of the list
+ * of smb_lkrng structs.
+ */
+
+ for(; blr->lock_num < num_locks; blr->lock_num++) {
+ count = IVAL(data,SMB_LKLEN_OFFSET(blr->lock_num));
+ offset = IVAL(data,SMB_LKOFF_OFFSET(blr->lock_num));
+ if(!do_lock(fsp,conn,count,offset, ((locktype & 1) ? F_RDLCK : F_WRLCK),
+ &eclass, &ecode))
+ break;
+ }
+
+ if(blr->lock_num == num_locks) {
+
+ /*
+ * Success - we got all the locks.
+ */
+
+ DEBUG(3,("blocking_lock_record_process fnum=%d type=%d num_locks=%d\n",
+ fsp->fnum, (unsigned int)locktype, num_locks) );
+
+ blocking_lock_reply_success(blr);
+ return True;
+
+ } else if((errno != EACCES) && (errno != EAGAIN)) {
+
+ /*
+ * We have other than a "can't get lock" POSIX
+ * error. Free any locks we had and return an error.
+ * Return True so we get dequeued.
+ */
+
+ blocking_lock_reply_error(blr, eclass, ecode);
+ return True;
+ }
+
+ /*
+ * Still can't get all the locks - keep waiting.
+ */
+
+ DEBUG(10,("blocking_lock_record_process: only got %d locks of %d needed for fnum = %d. \
+Waiting....\n", blr->lock_num, num_locks, fsp->fnum));
+
+ return False;
+}
+
+/****************************************************************************
+ Delete entries by fnum from the blocking lock pending queue.
+*****************************************************************************/
+
+void remove_pending_lock_requests_by_fid(files_struct *fsp)
+{
+ blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
+ blocking_lock_record *prev = NULL;
+
+ while(blr != NULL) {
+ files_struct *req_fsp = file_fsp(blr->inbuf,smb_vwv2);
+
+ if(req_fsp == fsp) {
+ free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
+ blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
+ continue;
+ }
+
+ prev = blr;
+ blr = (blocking_lock_record *)ubi_slNext(blr);
+ }
+}
+
+/****************************************************************************
+ Delete entries by mid from the blocking lock pending queue. Always send reply.
+*****************************************************************************/
+
+void remove_pending_lock_requests_by_mid(int mid)
+{
+ blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
+ blocking_lock_record *prev = NULL;
+
+ while(blr != NULL) {
+ if(SVAL(blr->inbuf,smb_mid) == mid) {
+ blocking_lock_reply_error(blr,0,NT_STATUS_CANCELLED);
+ free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
+ blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
+ continue;
+ }
+
+ prev = blr;
+ blr = (blocking_lock_record *)ubi_slNext(blr);
+ }
+}
+
+/****************************************************************************
+ Process the blocking lock queue. Note that this is only called as root.
+*****************************************************************************/
+
+void process_blocking_lock_queue(time_t t)
+{
+ blocking_lock_record *blr = (blocking_lock_record *)ubi_slFirst( &blocking_lock_queue );
+ blocking_lock_record *prev = NULL;
+
+ if(blr == NULL)
+ return;
+
+ /*
+ * Go through the queue and see if we can get any of the locks.
+ */
+
+ while(blr != NULL) {
+ files_struct *fsp = NULL;
+ connection_struct *conn = NULL;
+ uint16 vuid;
+
+ /*
+ * Ensure we don't have any old chain_fnum values
+ * sitting around....
+ */
+ file_chain_reset();
+
+ conn = conn_find(SVAL(blr->inbuf,smb_tid));
+ fsp = file_fsp(blr->inbuf,smb_vwv2);
+ vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
+ SVAL(blr->inbuf,smb_uid);
+
+ DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
+ fsp->fnum, fsp->fsp_name ));
+
+ if((blr->expire_time != -1) && (blr->expire_time > t)) {
+ /*
+ * Lock expired - throw away all previously
+ * obtained locks and return lock error.
+ */
+ DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
+ fsp->fnum, fsp->fsp_name ));
+
+ blocking_lock_reply_error(blr,ERRSRV,ERRaccess);
+ free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
+ blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
+ continue;
+ }
+
+ if(!become_user(conn,vuid)) {
+ DEBUG(0,("process_blocking_lock_queue: Unable to become user vuid=%d.\n",
+ vuid ));
+ /*
+ * Remove the entry and return an error to the client.
+ */
+ blocking_lock_reply_error(blr,ERRSRV,ERRaccess);
+ free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
+ blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
+ continue;
+ }
+
+ if(!become_service(conn,True)) {
+ DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
+ /*
+ * Remove the entry and return an error to the client.
+ */
+ blocking_lock_reply_error(blr,ERRSRV,ERRaccess);
+ free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
+ blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
+ unbecome_user();
+ continue;
+ }
+
+ /*
+ * Go through the remaining locks and try and obtain them.
+ * The call returns True if all locks were obtained successfully
+ * and False if we still need to wait.
+ */
+
+ if(blocking_lock_record_process(blr)) {
+ free_blocking_lock_record((blocking_lock_record *)ubi_slRemNext( &blocking_lock_queue, prev));
+ blr = (blocking_lock_record *)(prev ? ubi_slNext(prev) : ubi_slFirst(&blocking_lock_queue));
+ unbecome_user();
+ continue;
+ }
+
+ unbecome_user();
+
+ /*
+ * Move to the next in the list.
+ */
+ prev = blr;
+ blr = (blocking_lock_record *)ubi_slNext(blr);
+ }
+}
+