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Unix SMB/CIFS implementation.
3
Blocking Locking functions
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Copyright (C) Jeremy Allison 1998-2003
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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/****************************************************************************
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This is the structure to queue to implement blocking locks.
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notify. It consists of the requesting SMB and the expiry time.
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*****************************************************************************/
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typedef struct _blocking_lock_record {
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struct _blocking_lock_record *next;
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struct _blocking_lock_record *prev;
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enum brl_flavour lock_flav;
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enum brl_type lock_type;
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} blocking_lock_record;
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static blocking_lock_record *blocking_lock_queue;
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/****************************************************************************
47
Destructor for the above structure.
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****************************************************************************/
50
static void free_blocking_lock_record(blocking_lock_record *blr)
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DLIST_REMOVE(blocking_lock_queue, blr);
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SAFE_FREE(blr->inbuf);
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/****************************************************************************
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Determine if this is a secondary element of a chained SMB.
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**************************************************************************/
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static BOOL in_chained_smb(void)
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return (chain_size != 0);
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static void received_unlock_msg(int msg_type, struct process_id src,
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void *buf, size_t len);
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/****************************************************************************
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Function to push a blocking lock request onto the lock queue.
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****************************************************************************/
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BOOL push_blocking_lock_request( char *inbuf, int length,
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enum brl_type lock_type,
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enum brl_flavour lock_flav,
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SMB_BIG_UINT offset, SMB_BIG_UINT count)
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static BOOL set_lock_msg;
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blocking_lock_record *blr, *tmp;
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BOOL my_lock_ctx = False;
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struct byte_range_lock *br_lck = NULL;
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if(in_chained_smb() ) {
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DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
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* Now queue an entry on the blocking lock queue. We setup
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* the expiration time here.
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if((blr = SMB_MALLOC_P(blocking_lock_record)) == NULL) {
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DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
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if((blr->inbuf = (char *)SMB_MALLOC(length)) == NULL) {
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DEBUG(0,("push_blocking_lock_request: Malloc fail (2)!\n" ));
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blr->com_type = CVAL(inbuf,smb_com);
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blr->expire_time = (lock_timeout == -1) ? (time_t)-1 : time(NULL) + (time_t)lock_timeout;
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blr->lock_num = lock_num;
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blr->lock_pid = lock_pid;
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blr->lock_flav = lock_flav;
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blr->lock_type = lock_type;
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blr->offset = offset;
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memcpy(blr->inbuf, inbuf, length);
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blr->length = length;
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br_lck = brl_get_locks(NULL, blr->fsp);
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free_blocking_lock_record(blr);
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/* Add a pending lock record for this. */
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status = brl_lock(br_lck,
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if (!NT_STATUS_IS_OK(status)) {
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DEBUG(0,("push_blocking_lock_request: failed to add PENDING_LOCK record.\n"));
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free_blocking_lock_record(blr);
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DLIST_ADD_END(blocking_lock_queue, blr, tmp);
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/* Ensure we'll receive messages when this is unlocked. */
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message_register(MSG_SMB_UNLOCK, received_unlock_msg);
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DEBUG(3,("push_blocking_lock_request: lock request length=%d blocked with expiry time %d (+%d) \
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for fnum = %d, name = %s\n", length, (int)blr->expire_time, lock_timeout,
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blr->fsp->fnum, blr->fsp->fsp_name ));
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/* Push the MID of this packet on the signing queue. */
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srv_defer_sign_response(SVAL(inbuf,smb_mid));
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/****************************************************************************
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Return a smd with a given size.
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*****************************************************************************/
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static void send_blocking_reply(char *outbuf, int outsize)
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smb_setlen(outbuf,outsize - 4);
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if (!send_smb(smbd_server_fd(),outbuf))
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exit_server("send_blocking_reply: send_smb failed.");
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/****************************************************************************
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Return a lockingX success SMB.
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*****************************************************************************/
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static void reply_lockingX_success(blocking_lock_record *blr)
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char *outbuf = get_OutBuffer();
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int bufsize = BUFFER_SIZE;
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char *inbuf = blr->inbuf;
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construct_reply_common(inbuf, outbuf);
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set_message(outbuf,2,0,True);
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* As this message is a lockingX call we must handle
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* any following chained message correctly.
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* This is normally handled in construct_reply(),
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* but as that calls switch_message, we can't use
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* that here and must set up the chain info manually.
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outsize = chain_reply(inbuf,outbuf,blr->length,bufsize);
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outsize += chain_size;
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send_blocking_reply(outbuf,outsize);
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/****************************************************************************
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Return a generic lock fail error blocking call.
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*****************************************************************************/
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static void generic_blocking_lock_error(blocking_lock_record *blr, NTSTATUS status)
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char *outbuf = get_OutBuffer();
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char *inbuf = blr->inbuf;
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construct_reply_common(inbuf, outbuf);
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/* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
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FILE_LOCK_CONFLICT! (tridge) */
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if (NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
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status = NT_STATUS_FILE_LOCK_CONFLICT;
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if (!send_smb(smbd_server_fd(),outbuf))
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exit_server("generic_blocking_lock_error: send_smb failed.");
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/****************************************************************************
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Return a lock fail error for a lockingX call. Undo all the locks we have
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*****************************************************************************/
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static void reply_lockingX_error(blocking_lock_record *blr, NTSTATUS status)
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char *inbuf = blr->inbuf;
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files_struct *fsp = blr->fsp;
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uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
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SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT) 0;
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unsigned char locktype = CVAL(inbuf,smb_vwv3);
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BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
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data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
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* Data now points at the beginning of the list
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* of smb_lkrng structs.
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* Ensure we don't do a remove on the lock that just failed,
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* as under POSIX rules, if we have a lock already there, we
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* will delete it (and we shouldn't) .....
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for(i = blr->lock_num - 1; i >= 0; i--) {
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lock_pid = get_lock_pid( data, i, large_file_format);
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count = get_lock_count( data, i, large_file_format);
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offset = get_lock_offset( data, i, large_file_format, &err);
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* We know err cannot be set as if it was the lock
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* request would never have been queued. JRA.
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generic_blocking_lock_error(blr, status);
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/****************************************************************************
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Return a lock fail error.
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*****************************************************************************/
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static void blocking_lock_reply_error(blocking_lock_record *blr, NTSTATUS status)
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switch(blr->com_type) {
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/* We no longer push blocking lock requests for anything but lockingX and trans2. */
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generic_blocking_lock_error(blr, status);
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reply_lockingX_error(blr, status);
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char *outbuf = get_OutBuffer();
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char *inbuf = blr->inbuf;
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construct_reply_common(inbuf, outbuf);
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/* construct_reply_common has done us the favor to pre-fill the
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* command field with SMBtranss2 which is wrong :-)
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SCVAL(outbuf,smb_com,SMBtrans2);
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if (!send_smb(smbd_server_fd(),outbuf)) {
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exit_server("blocking_lock_reply_error: send_smb failed.");
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DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
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exit_server("PANIC - unknown type on blocking lock queue");
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/* We no longer push blocking lock requests for anything but lockingX and trans2. */
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/****************************************************************************
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Attempt to finish off getting all pending blocking locks for a lockread call.
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Returns True if we want to be removed from the list.
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*****************************************************************************/
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static BOOL process_lockread(blocking_lock_record *blr)
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char *outbuf = get_OutBuffer();
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char *inbuf = blr->inbuf;
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SMB_BIG_UINT startpos;
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files_struct *fsp = blr->fsp;
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BOOL my_lock_ctx = False;
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numtoread = SVAL(inbuf,smb_vwv1);
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startpos = (SMB_BIG_UINT)IVAL(inbuf,smb_vwv2);
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numtoread = MIN(BUFFER_SIZE-outsize,numtoread);
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data = smb_buf(outbuf) + 3;
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status = do_lock_spin(fsp,
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(uint32)SVAL(inbuf,smb_pid),
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(SMB_BIG_UINT)numtoread,
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if (NT_STATUS_V(status)) {
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if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
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!NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
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* We have other than a "can't get lock"
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* error. Send an error.
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* Return True so we get dequeued.
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generic_blocking_lock_error(blr, status);
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* Still waiting for lock....
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DEBUG(10,("process_lockread: failed to get lock for file = %s. Still waiting....\n",
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nread = read_file(fsp,data,startpos,numtoread);
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generic_blocking_lock_error(blr,NT_STATUS_ACCESS_DENIED);
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construct_reply_common(inbuf, outbuf);
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outsize = set_message(outbuf,5,0,True);
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SSVAL(outbuf,smb_vwv0,nread);
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SSVAL(outbuf,smb_vwv5,nread+3);
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SSVAL(p,0,nread); p += 2;
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set_message_end(outbuf, p+nread);
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DEBUG(3, ( "process_lockread file = %s, fnum=%d num=%lu nread=%ld\n",
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fsp->fsp_name, fsp->fnum, (unsigned long)numtoread, (long)nread ) );
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send_blocking_reply(outbuf,outsize);
400
/****************************************************************************
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Attempt to finish off getting all pending blocking locks for a lock call.
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Returns True if we want to be removed from the list.
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*****************************************************************************/
405
static BOOL process_lock(blocking_lock_record *blr)
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char *outbuf = get_OutBuffer();
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char *inbuf = blr->inbuf;
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SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
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files_struct *fsp = blr->fsp;
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BOOL my_lock_ctx = False;
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count = IVAL_TO_SMB_OFF_T(inbuf,smb_vwv1);
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offset = IVAL_TO_SMB_OFF_T(inbuf,smb_vwv3);
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status = do_lock_spin(fsp,
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(uint32)SVAL(inbuf,smb_pid),
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if (NT_STATUS_IS_ERR(status)) {
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if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
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!NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
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* We have other than a "can't get lock"
432
* error. Send an error.
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* Return True so we get dequeued.
436
blocking_lock_reply_error(blr, status);
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* Still can't get the lock - keep waiting.
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DEBUG(10,("process_lock: failed to get lock for file = %s. Still waiting....\n",
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* Success - we got the lock.
451
DEBUG(3,("process_lock : file=%s fnum=%d offset=%.0f count=%.0f\n",
452
fsp->fsp_name, fsp->fnum, (double)offset, (double)count));
454
construct_reply_common(inbuf, outbuf);
455
outsize = set_message(outbuf,0,0,True);
456
send_blocking_reply(outbuf,outsize);
461
/****************************************************************************
462
Attempt to finish off getting all pending blocking locks for a lockingX call.
463
Returns True if we want to be removed from the list.
464
*****************************************************************************/
466
static BOOL process_lockingX(blocking_lock_record *blr)
468
char *inbuf = blr->inbuf;
469
unsigned char locktype = CVAL(inbuf,smb_vwv3);
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files_struct *fsp = blr->fsp;
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uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
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uint16 num_locks = SVAL(inbuf,smb_vwv7);
473
SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
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BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
477
BOOL my_lock_ctx = False;
478
NTSTATUS status = NT_STATUS_OK;
480
data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
483
* Data now points at the beginning of the list
484
* of smb_lkrng structs.
487
for(; blr->lock_num < num_locks; blr->lock_num++) {
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lock_pid = get_lock_pid( data, blr->lock_num, large_file_format);
491
count = get_lock_count( data, blr->lock_num, large_file_format);
492
offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
495
* We know err cannot be set as if it was the lock
496
* request would never have been queued. JRA.
499
status = do_lock_spin(fsp,
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((locktype & 1) ? READ_LOCK : WRITE_LOCK),
507
if (NT_STATUS_IS_ERR(status)) {
512
if(blr->lock_num == num_locks) {
514
* Success - we got all the locks.
517
DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
518
fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
520
reply_lockingX_success(blr);
522
} else if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
523
!NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
525
* We have other than a "can't get lock"
526
* error. Free any locks we had and return an error.
527
* Return True so we get dequeued.
530
blocking_lock_reply_error(blr, status);
535
* Still can't get all the locks - keep waiting.
538
DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
540
blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
545
/****************************************************************************
546
Attempt to get the posix lock request from a SMBtrans2 call.
547
Returns True if we want to be removed from the list.
548
*****************************************************************************/
550
static BOOL process_trans2(blocking_lock_record *blr)
553
char *inbuf = blr->inbuf;
555
BOOL my_lock_ctx = False;
559
status = do_lock(blr->fsp,
567
if (!NT_STATUS_IS_OK(status)) {
568
if (ERROR_WAS_LOCK_DENIED(status)) {
569
/* Still can't get the lock, just keep waiting. */
573
* We have other than a "can't get lock"
574
* error. Send an error and return True so we get dequeued.
576
blocking_lock_reply_error(blr, status);
580
/* We finally got the lock, return success. */
581
outbuf = get_OutBuffer();
582
construct_reply_common(inbuf, outbuf);
583
SCVAL(outbuf,smb_com,SMBtrans2);
585
send_trans2_replies(outbuf, max_send, params, 2, NULL, 0);
590
/****************************************************************************
591
Process a blocking lock SMB.
592
Returns True if we want to be removed from the list.
593
*****************************************************************************/
595
static BOOL blocking_lock_record_process(blocking_lock_record *blr)
597
switch(blr->com_type) {
599
/* We no longer push blocking lock requests for anything but lockingX and trans2. */
601
return process_lock(blr);
603
return process_lockread(blr);
606
return process_lockingX(blr);
609
return process_trans2(blr);
611
DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
612
exit_server("PANIC - unknown type on blocking lock queue");
614
return False; /* Keep compiler happy. */
617
/****************************************************************************
618
Delete entries by fnum from the blocking lock pending queue.
619
*****************************************************************************/
621
void remove_pending_lock_requests_by_fid(files_struct *fsp)
623
blocking_lock_record *blr, *next = NULL;
625
for(blr = blocking_lock_queue; blr; blr = next) {
627
if(blr->fsp->fnum == fsp->fnum) {
628
struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
631
DEBUG(10,("remove_pending_lock_requests_by_fid - removing request type %d for \
632
file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
634
brl_remove_pending_lock(br_lck,
644
free_blocking_lock_record(blr);
649
/****************************************************************************
650
Delete entries by mid from the blocking lock pending queue. Always send reply.
651
*****************************************************************************/
653
void remove_pending_lock_requests_by_mid(int mid)
655
blocking_lock_record *blr, *next = NULL;
657
for(blr = blocking_lock_queue; blr; blr = next) {
659
if(SVAL(blr->inbuf,smb_mid) == mid) {
660
files_struct *fsp = blr->fsp;
661
struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
664
DEBUG(10,("remove_pending_lock_requests_by_mid - removing request type %d for \
665
file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
667
brl_remove_pending_lock(br_lck,
676
blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
677
free_blocking_lock_record(blr);
682
/****************************************************************************
683
Set a flag as an unlock request affects one of our pending locks.
684
*****************************************************************************/
686
static void received_unlock_msg(int msg_type, struct process_id src,
687
void *buf, size_t len)
689
DEBUG(10,("received_unlock_msg\n"));
690
process_blocking_lock_queue(time(NULL));
693
/****************************************************************************
694
Return the number of seconds to the next blocking locks timeout, or default_timeout
695
*****************************************************************************/
697
unsigned blocking_locks_timeout(unsigned default_timeout)
699
unsigned timeout = default_timeout;
701
blocking_lock_record *blr = blocking_lock_queue;
703
/* note that we avoid the time() syscall if there are no blocking locks */
709
for (; blr; blr = blr->next) {
710
if ((blr->expire_time != (time_t)-1) &&
711
(timeout > (blr->expire_time - t))) {
712
timeout = blr->expire_time - t;
722
/****************************************************************************
723
Process the blocking lock queue. Note that this is only called as root.
724
*****************************************************************************/
726
void process_blocking_lock_queue(time_t t)
728
blocking_lock_record *blr, *next = NULL;
731
* Go through the queue and see if we can get any of the locks.
734
for (blr = blocking_lock_queue; blr; blr = next) {
735
connection_struct *conn = NULL;
737
files_struct *fsp = NULL;
742
* Ensure we don't have any old chain_fsp values
749
conn = conn_find(SVAL(blr->inbuf,smb_tid));
750
vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
751
SVAL(blr->inbuf,smb_uid);
753
DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
754
fsp->fnum, fsp->fsp_name ));
756
if((blr->expire_time != -1) && (blr->expire_time <= t)) {
757
struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
760
* Lock expired - throw away all previously
761
* obtained locks and return lock error.
765
DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
766
fsp->fnum, fsp->fsp_name ));
768
brl_remove_pending_lock(br_lck,
777
blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
778
free_blocking_lock_record(blr);
782
if(!change_to_user(conn,vuid)) {
783
struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
786
* Remove the entry and return an error to the client.
790
brl_remove_pending_lock(br_lck,
799
DEBUG(0,("process_blocking_lock_queue: Unable to become user vuid=%d.\n",
801
blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
802
free_blocking_lock_record(blr);
806
if(!set_current_service(conn,SVAL(blr->inbuf,smb_flg),True)) {
807
struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
810
* Remove the entry and return an error to the client.
814
brl_remove_pending_lock(br_lck,
823
DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
824
blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
825
free_blocking_lock_record(blr);
826
change_to_root_user();
831
* Go through the remaining locks and try and obtain them.
832
* The call returns True if all locks were obtained successfully
833
* and False if we still need to wait.
836
if(blocking_lock_record_process(blr)) {
837
struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
840
brl_remove_pending_lock(br_lck,
849
free_blocking_lock_record(blr);
851
change_to_root_user();
added
removed
source/smbd/blocking.c
