path: root/source3/smbd/smb2_lock.c

/*
   Unix SMB/CIFS implementation.
   Core SMB2 server

   Copyright (C) Stefan Metzmacher 2009

   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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "smbd/globals.h"
#include "../libcli/smb/smb_common.h"

struct smbd_smb2_lock_element {
	uint64_t offset;
	uint64_t length;
	uint32_t flags;
};

static struct tevent_req *smbd_smb2_lock_send(TALLOC_CTX *mem_ctx,
						 struct tevent_context *ev,
						 struct smbd_smb2_request *smb2req,
						 uint32_t in_smbpid,
						 uint64_t in_file_id_volatile,
						 uint16_t in_lock_count,
						 struct smbd_smb2_lock_element *in_locks);
static NTSTATUS smbd_smb2_lock_recv(struct tevent_req *req);

static void smbd_smb2_request_lock_done(struct tevent_req *subreq);
NTSTATUS smbd_smb2_request_process_lock(struct smbd_smb2_request *req)
{
	const uint8_t *inhdr;
	const uint8_t *inbody;
	const int i = req->current_idx;
	size_t expected_body_size = 0x30;
	size_t body_size;
	uint32_t in_smbpid;
	uint16_t in_lock_count;
	uint64_t in_file_id_persistent;
	uint64_t in_file_id_volatile;
	struct smbd_smb2_lock_element *in_locks;
	struct tevent_req *subreq;
	const uint8_t *lock_buffer;
	uint16_t l;

	inhdr = (const uint8_t *)req->in.vector[i+0].iov_base;
	if (req->in.vector[i+1].iov_len != (expected_body_size & 0xFFFFFFFE)) {
		return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
	}

	inbody = (const uint8_t *)req->in.vector[i+1].iov_base;

	body_size = SVAL(inbody, 0x00);
	if (body_size != expected_body_size) {
		return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
	}

	in_smbpid			= IVAL(inhdr, SMB2_HDR_PID);

	in_lock_count			= CVAL(inbody, 0x02);
	/* 0x04 - 4 bytes reserved */
	in_file_id_persistent		= BVAL(inbody, 0x08);
	in_file_id_volatile		= BVAL(inbody, 0x10);

	if (in_lock_count < 1) {
		return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
	}

	if (((in_lock_count - 1) * 0x18) > req->in.vector[i+2].iov_len) {
		return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
	}

	if (req->compat_chain_fsp) {
		/* skip check */
	} else if (in_file_id_persistent != 0) {
		return smbd_smb2_request_error(req, NT_STATUS_FILE_CLOSED);
	}

	in_locks = talloc_array(req, struct smbd_smb2_lock_element,
				in_lock_count);
	if (in_locks == NULL) {
		return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
	}

	l = 0;
	lock_buffer = inbody + 0x18;

	in_locks[l].offset	= BVAL(lock_buffer, 0x00);
	in_locks[l].length	= BVAL(lock_buffer, 0x08);
	in_locks[l].flags	= IVAL(lock_buffer, 0x10);
	/* 0x14 - 4 reserved bytes */

	lock_buffer = (const uint8_t *)req->in.vector[i+2].iov_base;

	for (l=1; l < in_lock_count; l++) {
		in_locks[l].offset	= BVAL(lock_buffer, 0x00);
		in_locks[l].length	= BVAL(lock_buffer, 0x08);
		in_locks[l].flags	= IVAL(lock_buffer, 0x10);
		/* 0x14 - 4 reserved bytes */

		lock_buffer += 0x18;
	}

	subreq = smbd_smb2_lock_send(req,
				     req->sconn->smb2.event_ctx,
				     req,
				     in_smbpid,
				     in_file_id_volatile,
				     in_lock_count,
				     in_locks);
	if (subreq == NULL) {
		return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
	}
	tevent_req_set_callback(subreq, smbd_smb2_request_lock_done, req);

	return smbd_smb2_request_pending_queue(req, subreq);
}

static void smbd_smb2_request_lock_done(struct tevent_req *subreq)
{
	struct smbd_smb2_request *req = tevent_req_callback_data(subreq,
					struct smbd_smb2_request);
	DATA_BLOB outbody;
	NTSTATUS status;
	NTSTATUS error; /* transport error */

	if (req->cancelled) {
		const uint8_t *inhdr = (const uint8_t *)
			req->in.vector[req->current_idx].iov_base;
		uint64_t mid = BVAL(inhdr, SMB2_HDR_MESSAGE_ID);

		DEBUG(10,("smbd_smb2_request_lock_done: cancelled mid %llu\n",
			(unsigned long long)mid ));
		error = smbd_smb2_request_error(req, NT_STATUS_CANCELLED);
		if (!NT_STATUS_IS_OK(error)) {
			smbd_server_connection_terminate(req->sconn,
				nt_errstr(error));
			return;
		}
		return;
	}

	status = smbd_smb2_lock_recv(subreq);
	TALLOC_FREE(subreq);
	if (!NT_STATUS_IS_OK(status)) {
		error = smbd_smb2_request_error(req, status);
		if (!NT_STATUS_IS_OK(error)) {
			smbd_server_connection_terminate(req->sconn,
							 nt_errstr(error));
			return;
		}
		return;
	}

	outbody = data_blob_talloc(req->out.vector, NULL, 0x04);
	if (outbody.data == NULL) {
		error = smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
		if (!NT_STATUS_IS_OK(error)) {
			smbd_server_connection_terminate(req->sconn,
							 nt_errstr(error));
			return;
		}
		return;
	}

	SSVAL(outbody.data, 0x00, 0x04);	/* struct size */
	SSVAL(outbody.data, 0x02, 0);		/* reserved */

	error = smbd_smb2_request_done(req, outbody, NULL);
	if (!NT_STATUS_IS_OK(error)) {
		smbd_server_connection_terminate(req->sconn,
						 nt_errstr(error));
		return;
	}
}

struct smbd_smb2_lock_state {
	struct smbd_smb2_request *smb2req;
	struct smb_request *smb1req;
	struct blocking_lock_record *blr;
	uint16_t lock_count;
	struct smbd_lock_element *locks;
};

static struct tevent_req *smbd_smb2_lock_send(TALLOC_CTX *mem_ctx,
						 struct tevent_context *ev,
						 struct smbd_smb2_request *smb2req,
						 uint32_t in_smbpid,
						 uint64_t in_file_id_volatile,
						 uint16_t in_lock_count,
						 struct smbd_smb2_lock_element *in_locks)
{
	struct tevent_req *req;
	struct smbd_smb2_lock_state *state;
	struct smb_request *smb1req;
	connection_struct *conn = smb2req->tcon->compat_conn;
	files_struct *fsp;
	int32_t timeout = -1;
	bool isunlock = false;
	uint16_t i;
	struct smbd_lock_element *locks;
	NTSTATUS status;
	bool async = false;

	req = tevent_req_create(mem_ctx, &state,
			struct smbd_smb2_lock_state);
	if (req == NULL) {
		return NULL;
	}
	state->smb2req = smb2req;
	smb1req = smbd_smb2_fake_smb_request(smb2req);
	if (tevent_req_nomem(smb1req, req)) {
		return tevent_req_post(req, ev);
	}
	state->smb1req = smb1req;

	DEBUG(10,("smbd_smb2_lock_send: file_id[0x%016llX]\n",
		  (unsigned long long)in_file_id_volatile));

	fsp = file_fsp(smb1req, (uint16_t)in_file_id_volatile);
	if (fsp == NULL) {
		tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
		return tevent_req_post(req, ev);
	}
	if (conn != fsp->conn) {
		tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
		return tevent_req_post(req, ev);
	}
	if (smb2req->session->vuid != fsp->vuid) {
		tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
		return tevent_req_post(req, ev);
	}

	locks = talloc_array(state, struct smbd_lock_element, in_lock_count);
	if (locks == NULL) {
		tevent_req_nterror(req, NT_STATUS_NO_MEMORY);
		return tevent_req_post(req, ev);
	}

	switch (in_locks[0].flags) {
	case SMB2_LOCK_FLAG_SHARED:
	case SMB2_LOCK_FLAG_EXCLUSIVE:
		if (in_lock_count > 1) {
			tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
			return tevent_req_post(req, ev);
		}
		timeout = -1;
		break;

	case SMB2_LOCK_FLAG_SHARED|SMB2_LOCK_FLAG_FAIL_IMMEDIATELY:
	case SMB2_LOCK_FLAG_EXCLUSIVE|SMB2_LOCK_FLAG_FAIL_IMMEDIATELY:
		timeout = 0;
		break;

	case SMB2_LOCK_FLAG_UNLOCK:
		/* only the first lock gives the UNLOCK bit - see
		   MS-SMB2 3.3.5.14 */
		isunlock = true;
		timeout = 0;
		break;

	default:
		tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
		return tevent_req_post(req, ev);
	}

	for (i=0; i<in_lock_count; i++) {
		uint64_t max_count;
		bool invalid = false;

		switch (in_locks[i].flags) {
		case SMB2_LOCK_FLAG_SHARED:
		case SMB2_LOCK_FLAG_EXCLUSIVE:
			if (i > 0) {
				tevent_req_nterror(req,
						   NT_STATUS_INVALID_PARAMETER);
				return tevent_req_post(req, ev);
			}
			if (isunlock) {
				tevent_req_nterror(req,
						   NT_STATUS_INVALID_PARAMETER);
				return tevent_req_post(req, ev);
			}
			break;

		case SMB2_LOCK_FLAG_SHARED|SMB2_LOCK_FLAG_FAIL_IMMEDIATELY:
		case SMB2_LOCK_FLAG_EXCLUSIVE|SMB2_LOCK_FLAG_FAIL_IMMEDIATELY:
			if (isunlock) {
				tevent_req_nterror(req,
						   NT_STATUS_INVALID_PARAMETER);
				return tevent_req_post(req, ev);
			}
			break;

		case SMB2_LOCK_FLAG_UNLOCK:
			if (!isunlock) {
				tevent_req_nterror(req,
						   NT_STATUS_INVALID_PARAMETER);
				return tevent_req_post(req, ev);
			}
			break;

		default:
			if (isunlock) {
				/*
				 * is the first element was a UNLOCK
				 * we need to deferr the error response
				 * to the backend, because we need to process
				 * all unlock elements before
				 */
				invalid = true;
				break;
			}
			tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER);
			return tevent_req_post(req, ev);
		}

		locks[i].smbpid = in_smbpid;
		locks[i].offset = in_locks[i].offset;
		locks[i].count  = in_locks[i].length;

		if (in_locks[i].flags & SMB2_LOCK_FLAG_EXCLUSIVE) {
			locks[i].brltype = WRITE_LOCK;
		} else if (in_locks[i].flags & SMB2_LOCK_FLAG_SHARED) {
			locks[i].brltype = READ_LOCK;
		} else if (invalid) {
			/*
			 * this is an invalid UNLOCK element
			 * and the backend needs to test for
			 * brltype != UNLOCK_LOCK and return
			 * NT_STATUS_INVALID_PARAMER
			 */
			locks[i].brltype = READ_LOCK;
		} else {
			locks[i].brltype = UNLOCK_LOCK;
		}

		max_count = UINT64_MAX - locks[i].offset;
		if (locks[i].count > max_count) {
			tevent_req_nterror(req, NT_STATUS_INVALID_LOCK_RANGE);
			return tevent_req_post(req, ev);
		}
	}

	state->locks = locks;
	state->lock_count = in_lock_count;

	if (isunlock) {
		status = smbd_do_locking(smb1req, fsp,
					 0,
					 timeout,
					 in_lock_count,
					 locks,
					 0,
					 NULL,
					 &async);
	} else {
		status = smbd_do_locking(smb1req, fsp,
					 0,
					 timeout,
					 0,
					 NULL,
					 in_lock_count,
					 locks,
					 &async);
	}
	if (!NT_STATUS_IS_OK(status)) {
		if (NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
		       status = NT_STATUS_LOCK_NOT_GRANTED;
		}
		tevent_req_nterror(req, status);
		return tevent_req_post(req, ev);
	}

	if (async) {
		return req;
	}

	tevent_req_done(req);
	return tevent_req_post(req, ev);
}

static NTSTATUS smbd_smb2_lock_recv(struct tevent_req *req)
{
	NTSTATUS status;

	if (tevent_req_is_nterror(req, &status)) {
		tevent_req_received(req);
		return status;
	}

	tevent_req_received(req);
	return NT_STATUS_OK;
}

/****************************************************************
 Cancel an outstanding blocking lock request.
*****************************************************************/

static bool smbd_smb2_lock_cancel(struct tevent_req *req)
{
        struct smbd_smb2_request *smb2req = NULL;
        struct smbd_smb2_lock_state *state = tevent_req_data(req,
                                struct smbd_smb2_lock_state);
        if (!state) {
                return false;
        }

        if (!state->smb2req) {
                return false;
        }

        smb2req = state->smb2req;
        smb2req->cancelled = true;

        tevent_req_done(req);
        return true;
}

/****************************************************************
 Got a message saying someone unlocked a file. Re-schedule all
 blocking lock requests as we don't know if anything overlapped.
*****************************************************************/

static void received_unlock_msg(struct messaging_context *msg,
				void *private_data,
				uint32_t msg_type,
				struct server_id server_id,
				DATA_BLOB *data)
{
	DEBUG(10,("received_unlock_msg (SMB2)\n"));
	process_blocking_lock_queue_smb2();
}

/****************************************************************
 Function to get the blr on a pending record.
*****************************************************************/

struct blocking_lock_record *get_pending_smb2req_blr(struct smbd_smb2_request *smb2req)
{
	struct smbd_smb2_lock_state *state = NULL;
	const uint8_t *inhdr;

	if (!smb2req) {
		return NULL;
	}
	if (smb2req->subreq == NULL) {
		return NULL;
	}
	if (!tevent_req_is_in_progress(smb2req->subreq)) {
		return NULL;
	}
	inhdr = (const uint8_t *)smb2req->in.vector[smb2req->current_idx].iov_base;
	if (IVAL(inhdr, SMB2_HDR_OPCODE) != SMB2_OP_LOCK) {
		return NULL;
	}
	state = tevent_req_data(smb2req->subreq,
			struct smbd_smb2_lock_state);
	if (!state) {
		return NULL;
	}
	return state->blr;
}
/****************************************************************
 Set up the next brl timeout.
*****************************************************************/

static bool recalc_smb2_brl_timeout(struct smbd_server_connection *sconn)
{
	struct smbd_smb2_request *smb2req;
	struct timeval next_timeout = timeval_zero();
	int max_brl_timeout = lp_parm_int(-1, "brl", "recalctime", 5);

	/*
	 * If we already have a timeout event, don't replace it.
	 * It will fire before this one anyway.
	 */

	if (sconn->smb2.locks.brl_timeout) {
		DEBUG(10,("recalc_smb2_brl_timeout: timeout already exists\n"));
		return true;
	}

	for (smb2req = sconn->smb2.requests; smb2req; smb2req = smb2req->next) {
		struct blocking_lock_record *blr =
			get_pending_smb2req_blr(smb2req);
		if (blr && blr->blocking_pid == 0xFFFFFFFF) {
			/*
			 * If we're blocked on pid 0xFFFFFFFF this is
			 * a POSIX lock, so calculate a timeout of
			 * 10 seconds into the future.
			 */
			next_timeout = timeval_current_ofs(10, 0);
			break;
		}
	}

        /*
	 * To account for unclean shutdowns by clients we need a
	 * maximum timeout that we use for checking pending locks. If
	 * we have any pending locks at all, then check if the pending
	 * lock can continue at least every brl:recalctime seconds
	 * (default 5 seconds).
	 *
	 * This saves us needing to do a message_send_all() in the
	 * SIGCHLD handler in the parent daemon. That
	 * message_send_all() caused O(n^2) work to be done when IP
	 * failovers happened in clustered Samba, which could make the
	 * entire system unusable for many minutes.
	 */

	if (max_brl_timeout > 0) {
		struct timeval min_to = timeval_current_ofs(max_brl_timeout, 0);
		next_timeout = timeval_brl_min(&next_timeout, &min_to);
	}

	if (timeval_is_zero(&next_timeout)) {
		/* Infinite timeout - return. */
		DEBUG(10, ("push_blocking_lock_request_smb2: Next "
			"timeout = INFINITY\n"));
		return true;
	}

	if (DEBUGLVL(10)) {
		struct timeval cur, from_now;

		cur = timeval_current();
		from_now = timeval_until(&cur, &next_timeout);
		DEBUG(10, ("push_blocking_lock_request_smb2: Next "
			"timeout = %d.%d seconds from now.\n",
			(int)from_now.tv_sec, (int)from_now.tv_usec));
	}

	sconn->smb2.locks.brl_timeout = event_add_timed(
				smbd_event_context(),
				NULL,
				next_timeout,
				brl_timeout_fn,
				NULL);
	if (!sconn->smb2.locks.brl_timeout) {
		return false;
	}
	return true;
}

/****************************************************************
 Get an SMB2 lock reqeust to go async. lock_timeout should
 always be -1 here.
*****************************************************************/

bool push_blocking_lock_request_smb2( struct byte_range_lock *br_lck,
				struct smb_request *smb1req,
				files_struct *fsp,
				int lock_timeout,
				int lock_num,
				uint32_t lock_pid,
				enum brl_type lock_type,
				enum brl_flavour lock_flav,
				uint64_t offset,
				uint64_t count,
				uint32_t blocking_pid)
{
	struct smbd_server_connection *sconn = smbd_server_conn;
	struct smbd_smb2_request *smb2req = smb1req->smb2req;
	struct tevent_req *req = NULL;
	struct smbd_smb2_lock_state *state = NULL;
	NTSTATUS status = NT_STATUS_OK;

	SMB_ASSERT(lock_timeout == -1);

	if (!smb2req) {
		return false;
	}
	req = smb2req->subreq;
	if (!req) {
		return false;
	}
	state = tevent_req_data(req, struct smbd_smb2_lock_state);
	if (!state) {
		return false;
	}

	if (!state->blr) {
		struct blocking_lock_record *blr = talloc_zero(state,
					struct blocking_lock_record);
		if (!blr) {
			return false;
		}
		blr = talloc_zero(state, struct blocking_lock_record);
		blr->fsp = fsp;
		blr->expire_time.tv_sec = 0;
		blr->expire_time.tv_usec = 0; /* Never expire. */
		blr->lock_num = lock_num;
		blr->lock_pid = lock_pid;
		blr->blocking_pid = blocking_pid;
		blr->lock_flav = lock_flav;
		blr->lock_type = lock_type;
		blr->offset = offset;
		blr->count = count;

		/* Specific brl_lock() implementations can fill this in. */
		blr->blr_private = NULL;

		/* Add a pending lock record for this. */
		status = brl_lock(smbd_messaging_context(),
			br_lck,
			lock_pid,
			procid_self(),
			offset,
			count,
			lock_type == READ_LOCK ? PENDING_READ_LOCK : PENDING_WRITE_LOCK,
			blr->lock_flav,
			true,
			NULL,
			blr);

		if (!NT_STATUS_IS_OK(status)) {
			DEBUG(0,("push_blocking_lock_request_smb2: "
				"failed to add PENDING_LOCK record.\n"));
			TALLOC_FREE(blr);
			return false;
		}
		state->blr = blr;
	}

	recalc_smb2_brl_timeout(sconn);

	/* Ensure we'll receive messages when this is unlocked. */
	if (!sconn->smb2.locks.blocking_lock_unlock_state) {
		messaging_register(smbd_messaging_context(), NULL,
				MSG_SMB_UNLOCK, received_unlock_msg);
		sconn->smb2.locks.blocking_lock_unlock_state = true;
        }

	/* allow this request to be canceled */
	tevent_req_set_cancel_fn(req, smbd_smb2_lock_cancel);

	return true;
}

/****************************************************************
 Re-proccess a blocking lock request.
 This is equivalent to process_lockingX() inside smbd/blocking.c
*****************************************************************/

static void reprocess_blocked_smb2_lock(struct smbd_smb2_request *smb2req)
{
	NTSTATUS status;
	struct blocking_lock_record *blr = NULL;
	struct smbd_smb2_lock_state *state = NULL;
	files_struct *fsp = NULL;

	if (!smb2req->subreq) {
		return;
	}
	state = tevent_req_data(smb2req->subreq, struct smbd_smb2_lock_state);
	if (!state) {
		return;
	}

	blr = state->blr;
	fsp = blr->fsp;

	/* Try and finish off getting all the outstanding locks. */

	for (; blr->lock_num < state->lock_count; blr->lock_num++) {
		struct byte_range_lock *br_lck = NULL;
		struct smbd_lock_element *e = &state->locks[blr->lock_num];

		br_lck = do_lock(smbd_messaging_context(),
				fsp,
				e->smbpid,
				e->count,
				e->offset,
				e->brltype,
				WINDOWS_LOCK,
				true,
				&status,
				&blr->blocking_pid,
				blr);

		TALLOC_FREE(br_lck);

		if (NT_STATUS_IS_ERR(status)) {
			break;
		}
	}

	if(blr->lock_num == state->lock_count) {
		/*
		 * Success - we got all the locks.
		 */

		DEBUG(3,("reprocess_blocked_smb2_lock SUCCESS file = %s, "
			"fnum=%d num_locks=%d\n",
			fsp_str_dbg(fsp),
			fsp->fnum,
			(int)state->lock_count));

		tevent_req_done(smb2req->subreq);
		return;
	}

	if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
			!NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
		/*
		 * We have other than a "can't get lock"
		 * error. Return an error.
		 */
		tevent_req_nterror(smb2req->subreq, status);
		return;
        }

	/*
	 * Still can't get all the locks - keep waiting.
	 */

	DEBUG(10,("reprocess_blocked_smb2_lock: only got %d locks of %d needed "
		"for file %s, fnum = %d. Waiting....\n",
		(int)blr->lock_num,
		(int)state->lock_count,
		fsp_str_dbg(fsp),
		(int)fsp->fnum));

        return;

}

/****************************************************************
 Attempt to proccess all outstanding blocking locks pending on
 the request queue.
*****************************************************************/

void process_blocking_lock_queue_smb2(void)
{
	struct smbd_server_connection *sconn = smbd_server_conn;
	struct smbd_smb2_request *smb2req, *nextreq;

	for (smb2req = sconn->smb2.requests; smb2req; smb2req = nextreq) {
		const uint8_t *inhdr;

		nextreq = smb2req->next;

		if (smb2req->subreq == NULL) {
			/* This message has been processed. */
			continue;
		}
		if (!tevent_req_is_in_progress(smb2req->subreq)) {
			/* This message has been processed. */
			continue;
		}

		inhdr = (const uint8_t *)smb2req->in.vector[smb2req->current_idx].iov_base;
		if (IVAL(inhdr, SMB2_HDR_OPCODE) == SMB2_OP_LOCK) {
			reprocess_blocked_smb2_lock(smb2req);
		}
	}

	recalc_smb2_brl_timeout(sconn);
}

/****************************************************************************
 Remove any locks on this fd. Called from file_close().
****************************************************************************/

void cancel_pending_lock_requests_by_fid_smb2(files_struct *fsp,
			struct byte_range_lock *br_lck)
{
	struct smbd_server_connection *sconn = smbd_server_conn;
	struct smbd_smb2_request *smb2req, *nextreq;

	for (smb2req = sconn->smb2.requests; smb2req; smb2req = nextreq) {
		struct smbd_smb2_lock_state *state = NULL;
		files_struct *fsp_curr = NULL;
		int i = smb2req->current_idx;
		uint64_t in_file_id_volatile;
		struct blocking_lock_record *blr = NULL;
		const uint8_t *inhdr;
		const uint8_t *inbody;

		nextreq = smb2req->next;

		if (smb2req->subreq == NULL) {
			/* This message has been processed. */
			continue;
		}
		if (!tevent_req_is_in_progress(smb2req->subreq)) {
			/* This message has been processed. */
			continue;
		}

		inhdr = (const uint8_t *)smb2req->in.vector[i].iov_base;
		if (IVAL(inhdr, SMB2_HDR_OPCODE) != SMB2_OP_LOCK) {
			/* Not a lock call. */
			continue;
		}

		inbody = (const uint8_t *)smb2req->in.vector[i+1].iov_base;
		in_file_id_volatile = BVAL(inbody, 0x10);

		state = tevent_req_data(smb2req->subreq,
				struct smbd_smb2_lock_state);
		if (!state) {
			/* Strange - is this even possible ? */
			continue;
		}

		fsp_curr = file_fsp(state->smb1req, (uint16_t)in_file_id_volatile);
		if (fsp_curr == NULL) {
			/* Strange - is this even possible ? */
			continue;
		}

		if (fsp_curr != fsp) {
			/* It's not our fid */
			continue;
		}

		blr = state->blr;

		/* Remove the entries from the lock db. */
		brl_lock_cancel(br_lck,
				blr->lock_pid,
				procid_self(),
				blr->offset,
				blr->count,
				blr->lock_flav,
				blr);

		/* Finally cancel the request. */
		tevent_req_cancel(smb2req->subreq);
	}
}