samba-mirror/source3/locking/locking.c

/* 
   Unix SMB/CIFS implementation.
   Locking functions
   Copyright (C) Andrew Tridgell 1992-2000
   Copyright (C) Jeremy Allison 1992-2006
   Copyright (C) Volker Lendecke 2005

   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/>.

   Revision History:

   12 aug 96: Erik.Devriendt@te6.siemens.be
   added support for shared memory implementation of share mode locking

   May 1997. Jeremy Allison (jallison@whistle.com). Modified share mode
   locking to deal with multiple share modes per open file.

   September 1997. Jeremy Allison (jallison@whistle.com). Added oplock
   support.

   rewritten completely to use new tdb code. Tridge, Dec '99

   Added POSIX locking support. Jeremy Allison (jeremy@valinux.com), Apr. 2000.
   Added Unix Extensions POSIX locking support. Jeremy Allison Mar 2006.
*/

#include "includes.h"
#include "system/filesys.h"
#include "lib/util/server_id.h"
#include "locking/proto.h"
#include "smbd/globals.h"
#include "dbwrap/dbwrap.h"
#include "dbwrap/dbwrap_open.h"
#include "../libcli/security/security.h"
#include "serverid.h"
#include "messages.h"
#include "util_tdb.h"
#include "../librpc/gen_ndr/ndr_open_files.h"
#include "librpc/gen_ndr/ndr_file_id.h"
#include "locking/leases_db.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_LOCKING

#define NO_LOCKING_COUNT (-1)

/****************************************************************************
 Debugging aids :-).
****************************************************************************/

const char *lock_type_name(enum brl_type lock_type)
{
	switch (lock_type) {
		case READ_LOCK:
			return "READ";
		case WRITE_LOCK:
			return "WRITE";
		default:
			return "other";
	}
}

const char *lock_flav_name(enum brl_flavour lock_flav)
{
	return (lock_flav == WINDOWS_LOCK) ? "WINDOWS_LOCK" : "POSIX_LOCK";
}

/****************************************************************************
 Utility function called to see if a file region is locked.
 Called in the read/write codepath.
****************************************************************************/

void init_strict_lock_struct(files_struct *fsp,
				uint64_t smblctx,
				br_off start,
				br_off size,
				enum brl_type lock_type,
				struct lock_struct *plock)
{
	SMB_ASSERT(lock_type == READ_LOCK || lock_type == WRITE_LOCK);

	plock->context.smblctx = smblctx;
        plock->context.tid = fsp->conn->cnum;
        plock->context.pid = messaging_server_id(fsp->conn->sconn->msg_ctx);
        plock->start = start;
        plock->size = size;
        plock->fnum = fsp->fnum;
        plock->lock_type = lock_type;
        plock->lock_flav = lp_posix_cifsu_locktype(fsp);
}

bool strict_lock_check_default(files_struct *fsp, struct lock_struct *plock)
{
	struct byte_range_lock *br_lck;
	int strict_locking = lp_strict_locking(fsp->conn->params);
	bool ret = False;

	if (plock->size == 0) {
		return True;
	}

	if (!lp_locking(fsp->conn->params) || !strict_locking) {
		return True;
	}

	if (strict_locking == Auto) {
		uint32_t lease_type = fsp_lease_type(fsp);

		if ((lease_type & SMB2_LEASE_READ) &&
		     (plock->lock_type == READ_LOCK))
		{
			DBG_DEBUG("optimisation - read lease on file %s\n",
				  fsp_str_dbg(fsp));
			return true;
		}

		if ((lease_type & SMB2_LEASE_WRITE) &&
		     (plock->lock_type == WRITE_LOCK))
		{
			DBG_DEBUG("optimisation - write lease on file %s\n",
				  fsp_str_dbg(fsp));
			return true;
		}
	}

	br_lck = brl_get_locks_readonly(fsp);
	if (!br_lck) {
		return true;
	}
	ret = brl_locktest(br_lck, plock);

	if (!ret) {
		/*
		 * We got a lock conflict. Retry with rw locks to enable
		 * autocleanup. This is the slow path anyway.
		 */
		br_lck = brl_get_locks(talloc_tos(), fsp);
		if (br_lck == NULL) {
			return true;
		}
		ret = brl_locktest(br_lck, plock);
		TALLOC_FREE(br_lck);
	}

	DEBUG(10, ("strict_lock_default: flavour = %s brl start=%ju "
		   "len=%ju %s for fnum %ju file %s\n",
		   lock_flav_name(plock->lock_flav),
		   (uintmax_t)plock->start, (uintmax_t)plock->size,
		   ret ? "unlocked" : "locked",
		   (uintmax_t)plock->fnum, fsp_str_dbg(fsp)));

	return ret;
}

/****************************************************************************
 Find out if a lock could be granted - return who is blocking us if we can't.
****************************************************************************/

NTSTATUS query_lock(files_struct *fsp,
			uint64_t *psmblctx,
			uint64_t *pcount,
			uint64_t *poffset,
			enum brl_type *plock_type,
			enum brl_flavour lock_flav)
{
	struct byte_range_lock *br_lck = NULL;

	if (!fsp->can_lock) {
		return fsp->is_directory ? NT_STATUS_INVALID_DEVICE_REQUEST : NT_STATUS_INVALID_HANDLE;
	}

	if (!lp_locking(fsp->conn->params)) {
		return NT_STATUS_OK;
	}

	br_lck = brl_get_locks_readonly(fsp);
	if (!br_lck) {
		return NT_STATUS_NO_MEMORY;
	}

	return brl_lockquery(br_lck,
			psmblctx,
			messaging_server_id(fsp->conn->sconn->msg_ctx),
			poffset,
			pcount,
			plock_type,
			lock_flav);
}

static void increment_current_lock_count(files_struct *fsp,
    enum brl_flavour lock_flav)
{
	if (lock_flav == WINDOWS_LOCK &&
	    fsp->current_lock_count != NO_LOCKING_COUNT) {
		/* blocking ie. pending, locks also count here,
		 * as this is an efficiency counter to avoid checking
		 * the lock db. on close. JRA. */

		fsp->current_lock_count++;
	} else {
		/* Notice that this has had a POSIX lock request.
		 * We can't count locks after this so forget them.
		 */
		fsp->current_lock_count = NO_LOCKING_COUNT;
	}
}

static void decrement_current_lock_count(files_struct *fsp,
    enum brl_flavour lock_flav)
{
	if (lock_flav == WINDOWS_LOCK &&
	    fsp->current_lock_count != NO_LOCKING_COUNT) {
		SMB_ASSERT(fsp->current_lock_count > 0);
		fsp->current_lock_count--;
	}
}

/****************************************************************************
 Utility function called by locking requests.
****************************************************************************/

struct do_lock_state {
	struct files_struct *fsp;
	uint64_t smblctx;
	uint64_t count;
	uint64_t offset;
	enum brl_type lock_type;
	enum brl_flavour lock_flav;

	struct server_id blocker_pid;
	uint64_t blocker_smblctx;
	NTSTATUS status;
};

static void do_lock_fn(
	struct db_record *rec,
	bool *modified_dependent,
	void *private_data)
{
	struct do_lock_state *state = private_data;
	struct byte_range_lock *br_lck = NULL;

	br_lck = brl_get_locks(talloc_tos(), state->fsp);
	if (br_lck == NULL) {
		state->status = NT_STATUS_NO_MEMORY;
		return;
	}

	state->status = brl_lock(
		br_lck,
		state->smblctx,
		messaging_server_id(state->fsp->conn->sconn->msg_ctx),
		state->offset,
		state->count,
		state->lock_type,
		state->lock_flav,
		&state->blocker_pid,
		&state->blocker_smblctx);

	TALLOC_FREE(br_lck);
}

NTSTATUS do_lock(files_struct *fsp,
		 uint64_t smblctx,
		 uint64_t count,
		 uint64_t offset,
		 enum brl_type lock_type,
		 enum brl_flavour lock_flav,
		 struct server_id *pblocker_pid,
		 uint64_t *psmblctx)
{
	struct do_lock_state state = {
		.fsp = fsp,
		.smblctx = smblctx,
		.count = count,
		.offset = offset,
		.lock_type = lock_type,
		.lock_flav = lock_flav,
	};
	NTSTATUS status;

	/* silently return ok on print files as we don't do locking there */
	if (fsp->print_file) {
		return NT_STATUS_OK;
	}

	if (!fsp->can_lock) {
		if (fsp->is_directory) {
			return NT_STATUS_INVALID_DEVICE_REQUEST;
		}
		return NT_STATUS_INVALID_HANDLE;
	}

	if (!lp_locking(fsp->conn->params)) {
		return NT_STATUS_OK;
	}

	/* NOTE! 0 byte long ranges ARE allowed and should be stored  */

	DBG_DEBUG("lock flavour %s lock type %s start=%"PRIu64" len=%"PRIu64" "
		  "requested for %s file %s\n",
		  lock_flav_name(lock_flav),
		  lock_type_name(lock_type),
		  offset,
		  count,
		  fsp_fnum_dbg(fsp),
		  fsp_str_dbg(fsp));

	status = share_mode_do_locked(fsp->file_id, do_lock_fn, &state);
	if (!NT_STATUS_IS_OK(status)) {
		DBG_DEBUG("share_mode_do_locked returned %s\n",
			  nt_errstr(status));
		return status;
	}

	if (psmblctx != NULL) {
		*psmblctx = state.blocker_smblctx;
	}
	if (pblocker_pid != NULL) {
		*pblocker_pid = state.blocker_pid;
	}

	DBG_DEBUG("returning status=%s\n", nt_errstr(state.status));

	increment_current_lock_count(fsp, lock_flav);

	return state.status;
}

/****************************************************************************
 Utility function called by unlocking requests.
****************************************************************************/

NTSTATUS do_unlock(files_struct *fsp,
		   uint64_t smblctx,
		   uint64_t count,
		   uint64_t offset,
		   enum brl_flavour lock_flav)
{
	bool ok = False;
	struct byte_range_lock *br_lck = NULL;

	if (!fsp->can_lock) {
		return fsp->is_directory ? NT_STATUS_INVALID_DEVICE_REQUEST : NT_STATUS_INVALID_HANDLE;
	}

	if (!lp_locking(fsp->conn->params)) {
		return NT_STATUS_OK;
	}

	DBG_DEBUG("unlock start=%"PRIu64" len=%"PRIu64" requested for %s file "
		  "%s\n",
		  offset,
		  count,
		  fsp_fnum_dbg(fsp),
		  fsp_str_dbg(fsp));

	br_lck = brl_get_locks(talloc_tos(), fsp);
	if (!br_lck) {
		return NT_STATUS_NO_MEMORY;
	}

	ok = brl_unlock(br_lck,
			smblctx,
			messaging_server_id(fsp->conn->sconn->msg_ctx),
			offset,
			count,
			lock_flav);

	TALLOC_FREE(br_lck);

	if (!ok) {
		DEBUG(10,("do_unlock: returning ERRlock.\n" ));
		return NT_STATUS_RANGE_NOT_LOCKED;
	}

	decrement_current_lock_count(fsp, lock_flav);
	return NT_STATUS_OK;
}

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

void locking_close_file(files_struct *fsp,
			enum file_close_type close_type)
{
	struct byte_range_lock *br_lck;

	if (!lp_locking(fsp->conn->params)) {
		return;
	}

	/* If we have no outstanding locks or pending
	 * locks then we don't need to look in the lock db.
	 */

	if (fsp->current_lock_count == 0) {
		return;
	}

	br_lck = brl_get_locks(talloc_tos(),fsp);

	if (br_lck) {
		/*
		 * Unlocks must trigger dbwrap_watch watchers,
		 * normally in smbd_do_unlocking. Here it's done
		 * implictly, we're closing the file and thus remove a
		 * share mode. This will wake the waiters.
		 */
		brl_close_fnum(br_lck);
		TALLOC_FREE(br_lck);
	}
}

/*******************************************************************
 Print out a share mode.
********************************************************************/

char *share_mode_str(TALLOC_CTX *ctx, int num,
		     const struct file_id *id,
		     const struct share_mode_entry *e)
{
	struct server_id_buf tmp;

	return talloc_asprintf(ctx, "share_mode_entry[%d]: "
		 "pid = %s, share_access = 0x%x, private_options = 0x%x, "
		 "access_mask = 0x%x, mid = 0x%llx, type= 0x%x, gen_id = %llu, "
		 "uid = %u, flags = %u, file_id %s, name_hash = 0x%x",
		 num,
		 server_id_str_buf(e->pid, &tmp),
		 e->share_access, e->private_options,
		 e->access_mask, (unsigned long long)e->op_mid,
		 e->op_type, (unsigned long long)e->share_file_id,
		 (unsigned int)e->uid, (unsigned int)e->flags,
		 file_id_string_tos(id),
		 (unsigned int)e->name_hash);
}

/*******************************************************************
 Fetch a share mode where we know one MUST exist. This call reference
 counts it internally to allow for nested lock fetches.
********************************************************************/

struct share_mode_lock *get_existing_share_mode_lock(TALLOC_CTX *mem_ctx,
						     const struct file_id id)
{
	return get_share_mode_lock(mem_ctx, id, NULL, NULL, NULL);
}

static bool rename_lease_fn(struct share_mode_lock *lck,
			    struct share_mode_entry *e,
			    void *private_data)
{
	struct share_mode_data *d = lck->data;
	NTSTATUS status;

	status = leases_db_rename(&e->client_guid,
				  &e->lease_key,
				  &d->id,
				  d->servicepath,
				  d->base_name,
				  d->stream_name);

	if (!NT_STATUS_IS_OK(status)) {
		/* Any error recovery possible here ? */
		DBG_WARNING("Failed to rename lease key for "
			    "renamed file %s:%s. %s\n",
			    d->base_name,
			    d->stream_name,
			    nt_errstr(status));
	}

	return false;
}

/*******************************************************************
 Sets the service name and filename for rename.
 At this point we emit "file renamed" messages to all
 process id's that have this file open.
 Based on an initial code idea from SATOH Fumiyasu <fumiya@samba.gr.jp>
********************************************************************/

bool rename_share_filename(struct messaging_context *msg_ctx,
			struct share_mode_lock *lck,
			struct file_id id,
			const char *servicepath,
			uint32_t orig_name_hash,
			uint32_t new_name_hash,
			const struct smb_filename *smb_fname_dst)
{
	struct share_mode_data *d = lck->data;
	struct file_rename_message msg = {
		.id = id,
		.servicepath = servicepath,
		.base_name = smb_fname_dst->base_name,
		.stream_name = smb_fname_dst->stream_name,
	};
	uint32_t i;
	struct server_id self_pid = messaging_server_id(msg_ctx);
	bool ok;

	DEBUG(10, ("rename_share_filename: servicepath %s newname %s\n",
		   servicepath, smb_fname_dst->base_name));

	/*
	 * rename_internal_fsp() and rename_internals() add './' to
	 * head of newname if newname does not contain a '/'.
	 */

	if (strncmp(msg.base_name, "./", 2) == 0) {
		msg.base_name += 2;
	}

	d->servicepath = talloc_strdup(d, msg.servicepath);
	d->base_name = talloc_strdup(d, msg.base_name);
	d->stream_name = talloc_strdup(d, msg.stream_name);
	if ((d->servicepath == NULL) ||
	    (d->base_name == NULL) ||
	    ((msg.stream_name != NULL) && (d->stream_name == NULL))) {
		DBG_WARNING("talloc failed\n");
		return false;
	}
	d->modified = True;

	/* Send the messages. */
	for (i=0; i<d->num_share_modes; i++) {
		struct share_mode_entry *se = &d->share_modes[i];
		DATA_BLOB blob;
		enum ndr_err_code ndr_err;

		if (!is_valid_share_mode_entry(se)) {
			continue;
		}

		/* If this is a hardlink to the inode
		   with a different name, skip this. */
		if (se->name_hash != orig_name_hash) {
			continue;
		}

		se->name_hash = new_name_hash;

		/* But not to ourselves... */
		if (serverid_equal(&se->pid, &self_pid)) {
			continue;
		}

		if (share_mode_stale_pid(d, i)) {
			continue;
		}

		msg.share_file_id = se->share_file_id;

		ndr_err = ndr_push_struct_blob(
			&blob,
			talloc_tos(),
			&msg,
			(ndr_push_flags_fn_t)ndr_push_file_rename_message);
		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
			DBG_DEBUG("ndr_push_file_rename_message failed: %s\n",
				  ndr_errstr(ndr_err));
			return false;
		}
		if (DEBUGLEVEL >= 10) {
			struct server_id_buf tmp;
			DBG_DEBUG("sending rename message to %s\n",
				  server_id_str_buf(se->pid, &tmp));
			NDR_PRINT_DEBUG(file_rename_message, &msg);
		}

		messaging_send(msg_ctx, se->pid, MSG_SMB_FILE_RENAME, &blob);

		TALLOC_FREE(blob.data);
	}

	ok = share_mode_forall_leases(lck, rename_lease_fn, NULL);
	if (!ok) {
		/*
		 * Ignore error here. Not sure what to do..
		 */
		DBG_WARNING("share_mode_forall_leases failed\n");
	}

	return True;
}

void get_file_infos(struct file_id id,
		    uint32_t name_hash,
		    bool *delete_on_close,
		    struct timespec *write_time)
{
	struct share_mode_lock *lck;

	if (delete_on_close) {
		*delete_on_close = false;
	}

	if (write_time) {
		ZERO_STRUCTP(write_time);
	}

	if (!(lck = fetch_share_mode_unlocked(talloc_tos(), id))) {
		return;
	}

	if (delete_on_close) {
		*delete_on_close = is_delete_on_close_set(lck, name_hash);
	}

	if (write_time) {
		*write_time = get_share_mode_write_time(lck);
	}

	TALLOC_FREE(lck);
}

bool is_valid_share_mode_entry(const struct share_mode_entry *e)
{
	int num_props = 0;

	if (e->stale) {
		return false;
	}

	num_props += ((e->op_type == NO_OPLOCK) ? 1 : 0);
	num_props += (EXCLUSIVE_OPLOCK_TYPE(e->op_type) ? 1 : 0);
	num_props += (LEVEL_II_OPLOCK_TYPE(e->op_type) ? 1 : 0);
	num_props += (e->op_type == LEASE_OPLOCK);

	if ((num_props > 1) && serverid_exists(&e->pid)) {
		smb_panic("Invalid share mode entry");
	}
	return (num_props != 0);
}

NTSTATUS remove_lease_if_stale(const struct share_mode_data *d,
			       const struct GUID *client_guid,
			       const struct smb2_lease_key *lease_key)
{
	uint32_t i;
	NTSTATUS status;

	for (i=0; i<d->num_share_modes; i++) {
		const struct share_mode_entry *e = &d->share_modes[i];
		bool same;

		if (e->stale) {
			continue;
		}
		if (e->op_type != LEASE_OPLOCK) {
			continue;
		}

		same = smb2_lease_equal(
			&e->client_guid,
			&e->lease_key,
			client_guid,
			lease_key);
		if (same) {
			return NT_STATUS_RESOURCE_IN_USE;
		}
	}

	status = leases_db_del(client_guid, lease_key, &d->id);
	if (!NT_STATUS_IS_OK(status)) {
		DBG_DEBUG("leases_db_del failed: %s\n",
			  nt_errstr(status));
	}
	return status;
}

/*
 * See if we need to remove a lease being referred to by a
 * share mode that is being marked stale or deleted.
 */

static void remove_share_mode_lease(struct share_mode_data *d,
				    struct share_mode_entry *e)
{
	uint16_t op_type;

	op_type = e->op_type;
	e->op_type = NO_OPLOCK;

	d->modified = true;

	if (op_type != LEASE_OPLOCK) {
		return;
	}

	remove_lease_if_stale(d, &e->client_guid, &e->lease_key);
}

/*
 * In case d->share_modes[i] conflicts with something or otherwise is
 * being used, we need to make sure the corresponding process still
 * exists.
 */
bool share_mode_stale_pid(struct share_mode_data *d, uint32_t idx)
{
	struct server_id_buf tmp;
	struct share_mode_entry *e;

	if (idx > d->num_share_modes) {
		DBG_WARNING("Asking for index %"PRIu32", "
			    "only %"PRIu32" around\n",
			    idx,
			    d->num_share_modes);
		return false;
	}
	e = &d->share_modes[idx];
	if (e->stale) {
		/*
		 * Checked before
		 */
		return true;
	}
	if (serverid_exists(&e->pid)) {
		DBG_DEBUG("PID %s (index %"PRIu32" out of %"PRIu32") "
			  "still exists\n",
			  server_id_str_buf(e->pid, &tmp),
			  idx,
			  d->num_share_modes);
		return false;
	}
	DBG_DEBUG("PID %s (index %"PRIu32" out of %"PRIu32") "
		  "does not exist anymore\n",
		  server_id_str_buf(e->pid, &tmp),
		  idx,
		  d->num_share_modes);

	e->stale = true;

	if (d->num_delete_tokens != 0) {
		uint32_t i;

		for (i=0; i<d->num_share_modes; i++) {
			bool valid = !d->share_modes[i].stale;
			if (valid) {
				break;
			}
		}

		if (i == d->num_share_modes) {
			/*
			 * No valid (non-stale) share mode found, all
			 * who might have set the delete token are
			 * gone.
			 */
			TALLOC_FREE(d->delete_tokens);
			d->num_delete_tokens = 0;
		}
	}

	remove_share_mode_lease(d, e);

	d->modified = true;
	return true;
}

void remove_stale_share_mode_entries(struct share_mode_data *d)
{
	uint32_t i;

	i = 0;
	while (i < d->num_share_modes) {
		if (d->share_modes[i].stale) {
			struct share_mode_entry *m = d->share_modes;
			m[i] = m[d->num_share_modes-1];
			d->num_share_modes -= 1;
			continue;
		}
		i += 1;
	}
}

bool set_share_mode(struct share_mode_lock *lck,
		    struct files_struct *fsp,
		    uid_t uid,
		    uint64_t mid,
		    uint16_t op_type,
		    uint32_t share_access,
		    uint32_t access_mask)
{
	struct share_mode_data *d = lck->data;
	struct share_mode_entry *tmp, *e;

	tmp = talloc_realloc(d, d->share_modes, struct share_mode_entry,
			     d->num_share_modes+1);
	if (tmp == NULL) {
		return false;
	}
	d->share_modes = tmp;
	e = &d->share_modes[d->num_share_modes];
	d->num_share_modes += 1;
	d->modified = true;

	ZERO_STRUCTP(e);
	e->pid = messaging_server_id(fsp->conn->sconn->msg_ctx);
	e->share_access = share_access;
	e->private_options = fsp->fh->private_options;
	e->access_mask = access_mask;
	e->op_mid = mid;
	e->op_type = op_type;

	if (op_type == LEASE_OPLOCK) {
		const struct GUID *client_guid = fsp_client_guid(fsp);
		e->client_guid = *client_guid;
		e->lease_key = fsp->lease->lease.lease_key;
	}

	e->time.tv_sec = fsp->open_time.tv_sec;
	e->time.tv_usec = fsp->open_time.tv_usec;
	e->share_file_id = fsp->fh->gen_id;
	e->uid = (uint32_t)uid;
	e->flags = (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) ?
		SHARE_MODE_FLAG_POSIX_OPEN : 0;
	e->name_hash = fsp->name_hash;

	return true;
}

static struct share_mode_entry *find_share_mode_entry(
	struct share_mode_lock *lck, files_struct *fsp)
{
	struct share_mode_data *d = lck->data;
	struct server_id pid;
	uint32_t i;

	pid = messaging_server_id(fsp->conn->sconn->msg_ctx);

	for (i=0; i<d->num_share_modes; i++) {
		struct share_mode_entry *e = &d->share_modes[i];

		if (!is_valid_share_mode_entry(e)) {
			continue;
		}
		if (!serverid_equal(&pid, &e->pid)) {
			continue;
		}
		if (fsp->fh->gen_id != e->share_file_id) {
			continue;
		}
		return e;
	}
	return NULL;
}

/*******************************************************************
 Del the share mode of a file for this process.
********************************************************************/

bool del_share_mode(struct share_mode_lock *lck, files_struct *fsp)
{
	struct share_mode_entry *e;

	e = find_share_mode_entry(lck, fsp);
	if (e == NULL) {
		return False;
	}
	remove_share_mode_lease(lck->data, e);
	*e = lck->data->share_modes[lck->data->num_share_modes-1];
	lck->data->num_share_modes -= 1;
	lck->data->modified = True;
	return True;
}

bool mark_share_mode_disconnected(struct share_mode_lock *lck,
				  struct files_struct *fsp)
{
	struct share_mode_entry *e;

	if (lck->data->num_share_modes != 1) {
		return false;
	}

	if (fsp->op == NULL) {
		return false;
	}
	if (!fsp->op->global->durable) {
		return false;
	}

	e = find_share_mode_entry(lck, fsp);
	if (e == NULL) {
		return false;
	}

	DEBUG(10, ("Marking share mode entry disconnected for durable handle\n"));

	server_id_set_disconnected(&e->pid);

	/*
	 * On reopen the caller needs to check that
	 * the client comes with the correct handle.
	 */
	e->share_file_id = fsp->op->global->open_persistent_id;

	lck->data->modified = true;
	return true;
}

/*******************************************************************
 Remove an oplock mid and mode entry from a share mode.
********************************************************************/

bool remove_share_oplock(struct share_mode_lock *lck, files_struct *fsp)
{
	struct share_mode_data *d = lck->data;
	struct share_mode_entry *e;

	e = find_share_mode_entry(lck, fsp);
	if (e == NULL) {
		return False;
	}

	remove_share_mode_lease(d, e);
	d->modified = True;
	return true;
}

/*******************************************************************
 Downgrade a oplock type from exclusive to level II.
********************************************************************/

bool downgrade_share_oplock(struct share_mode_lock *lck, files_struct *fsp)
{
	struct share_mode_entry *e;

	e = find_share_mode_entry(lck, fsp);
	if (e == NULL) {
		return False;
	}

	e->op_type = LEVEL_II_OPLOCK;
	lck->data->flags |= SHARE_MODE_HAS_READ_LEASE;
	lck->data->modified = True;
	return True;
}

/****************************************************************************
 Adds a delete on close token.
****************************************************************************/

static bool add_delete_on_close_token(struct share_mode_data *d,
			uint32_t name_hash,
			const struct security_token *nt_tok,
			const struct security_unix_token *tok)
{
	struct delete_token *tmp, *dtl;

	tmp = talloc_realloc(d, d->delete_tokens, struct delete_token,
			     d->num_delete_tokens+1);
	if (tmp == NULL) {
		return false;
	}
	d->delete_tokens = tmp;
	dtl = &d->delete_tokens[d->num_delete_tokens];

	dtl->name_hash = name_hash;
	dtl->delete_nt_token = dup_nt_token(d->delete_tokens, nt_tok);
	if (dtl->delete_nt_token == NULL) {
		return false;
	}
	dtl->delete_token = copy_unix_token(d->delete_tokens, tok);
	if (dtl->delete_token == NULL) {
		return false;
	}
	d->num_delete_tokens += 1;
	d->modified = true;
	return true;
}

void reset_delete_on_close_lck(files_struct *fsp,
			       struct share_mode_lock *lck)
{
	struct share_mode_data *d = lck->data;
	uint32_t i;

	for (i=0; i<d->num_delete_tokens; i++) {
		struct delete_token *dt = &d->delete_tokens[i];

		if (dt->name_hash == fsp->name_hash) {
			d->modified = true;

			/* Delete this entry. */
			TALLOC_FREE(dt->delete_nt_token);
			TALLOC_FREE(dt->delete_token);
			*dt = d->delete_tokens[d->num_delete_tokens-1];
			d->num_delete_tokens -= 1;
		}
	}
}

/****************************************************************************
 Sets the delete on close flag over all share modes on this file.
 Modify the share mode entry for all files open
 on this device and inode to tell other smbds we have
 changed the delete on close flag. This will be noticed
 in the close code, the last closer will delete the file
 if flag is set.
 This makes a copy of any struct security_unix_token into the
 lck entry. This function is used when the lock is already granted.
****************************************************************************/

void set_delete_on_close_lck(files_struct *fsp,
			struct share_mode_lock *lck,
			const struct security_token *nt_tok,
			const struct security_unix_token *tok)
{
	struct messaging_context *msg_ctx = fsp->conn->sconn->msg_ctx;
	struct share_mode_data *d = lck->data;
	uint32_t i;
	bool ret;
	DATA_BLOB fid_blob = {};
	enum ndr_err_code ndr_err;

	SMB_ASSERT(nt_tok != NULL);
	SMB_ASSERT(tok != NULL);

	for (i=0; i<d->num_delete_tokens; i++) {
		struct delete_token *dt = &d->delete_tokens[i];
		if (dt->name_hash == fsp->name_hash) {
			d->modified = true;

			/* Replace this token with the given tok. */
			TALLOC_FREE(dt->delete_nt_token);
			dt->delete_nt_token = dup_nt_token(dt, nt_tok);
			SMB_ASSERT(dt->delete_nt_token != NULL);
			TALLOC_FREE(dt->delete_token);
			dt->delete_token = copy_unix_token(dt, tok);
			SMB_ASSERT(dt->delete_token != NULL);

			return;
		}
	}

	ret = add_delete_on_close_token(lck->data, fsp->name_hash, nt_tok, tok);
	SMB_ASSERT(ret);

	ndr_err = ndr_push_struct_blob(&fid_blob, talloc_tos(), &fsp->file_id,
				       (ndr_push_flags_fn_t)ndr_push_file_id);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		DEBUG(10, ("ndr_push_file_id failed: %s\n",
			   ndr_errstr(ndr_err)));
	}

	for (i=0; i<d->num_share_modes; i++) {
		struct share_mode_entry *e = &d->share_modes[i];
		NTSTATUS status;

		status = messaging_send(
			msg_ctx, e->pid, MSG_SMB_NOTIFY_CANCEL_DELETED,
			&fid_blob);

		if (!NT_STATUS_IS_OK(status)) {
			struct server_id_buf tmp;
			DEBUG(10, ("%s: messaging_send to %s returned %s\n",
				   __func__, server_id_str_buf(e->pid, &tmp),
				   nt_errstr(status)));
		}
	}

	TALLOC_FREE(fid_blob.data);
}

bool set_delete_on_close(files_struct *fsp, bool delete_on_close,
			const struct security_token *nt_tok,
			const struct security_unix_token *tok)
{
	struct share_mode_lock *lck;

	DEBUG(10,("set_delete_on_close: %s delete on close flag for "
		  "%s, file %s\n",
		  delete_on_close ? "Adding" : "Removing", fsp_fnum_dbg(fsp),
		  fsp_str_dbg(fsp)));

	lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
	if (lck == NULL) {
		return False;
	}

	if (delete_on_close) {
		set_delete_on_close_lck(fsp, lck, nt_tok, tok);
	} else {
		reset_delete_on_close_lck(fsp, lck);
	}

	if (fsp->is_directory) {
		SMB_ASSERT(!is_ntfs_stream_smb_fname(fsp->fsp_name));
		send_stat_cache_delete_message(fsp->conn->sconn->msg_ctx,
					       fsp->fsp_name->base_name);
	}

	TALLOC_FREE(lck);

	fsp->delete_on_close = delete_on_close;

	return True;
}

static struct delete_token *find_delete_on_close_token(
	struct share_mode_data *d, uint32_t name_hash)
{
	uint32_t i;

	DEBUG(10, ("find_delete_on_close_token: name_hash = 0x%x\n",
		   (unsigned int)name_hash));

	for (i=0; i<d->num_delete_tokens; i++) {
		struct delete_token *dt = &d->delete_tokens[i];

		DEBUG(10, ("find__delete_on_close_token: dt->name_hash = 0x%x\n",
			   (unsigned int)dt->name_hash ));
		if (dt->name_hash == name_hash) {
			return dt;
		}
	}
	return NULL;
}

/****************************************************************************
 Return the NT token and UNIX token if there's a match. Return true if
 found, false if not.
****************************************************************************/

bool get_delete_on_close_token(struct share_mode_lock *lck,
					uint32_t name_hash,
					const struct security_token **pp_nt_tok,
					const struct security_unix_token **pp_tok)
{
	struct delete_token *dt;

	dt = find_delete_on_close_token(lck->data, name_hash);
	if (dt == NULL) {
		return false;
	}
	*pp_nt_tok = dt->delete_nt_token;
	*pp_tok =  dt->delete_token;
	return true;
}

bool is_delete_on_close_set(struct share_mode_lock *lck, uint32_t name_hash)
{
	return find_delete_on_close_token(lck->data, name_hash) != NULL;
}

bool set_sticky_write_time(struct file_id fileid, struct timespec write_time)
{
	struct share_mode_lock *lck;

	DEBUG(5,("set_sticky_write_time: %s id=%s\n",
		 timestring(talloc_tos(),
			    convert_timespec_to_time_t(write_time)),
		 file_id_string_tos(&fileid)));

	lck = get_existing_share_mode_lock(talloc_tos(), fileid);
	if (lck == NULL) {
		return False;
	}

	if (timespec_compare(&lck->data->changed_write_time, &write_time) != 0) {
		lck->data->modified = True;
		lck->data->changed_write_time = write_time;
	}

	TALLOC_FREE(lck);
	return True;
}

bool set_write_time(struct file_id fileid, struct timespec write_time)
{
	struct share_mode_lock *lck;

	DEBUG(5,("set_write_time: %s id=%s\n",
		 timestring(talloc_tos(),
			    convert_timespec_to_time_t(write_time)),
		 file_id_string_tos(&fileid)));

	lck = get_existing_share_mode_lock(talloc_tos(), fileid);
	if (lck == NULL) {
		return False;
	}

	if (timespec_compare(&lck->data->old_write_time, &write_time) != 0) {
		lck->data->modified = True;
		lck->data->old_write_time = write_time;
	}

	TALLOC_FREE(lck);
	return True;
}

struct timespec get_share_mode_write_time(struct share_mode_lock *lck)
{
	struct share_mode_data *d = lck->data;

	if (!null_timespec(d->changed_write_time)) {
		return d->changed_write_time;
	}
	return d->old_write_time;
}

bool file_has_open_streams(files_struct *fsp)
{
	struct share_mode_lock *lock = NULL;
	struct share_mode_data *d = NULL;
	uint32_t i;

	lock = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
	if (lock == NULL) {
		return false;
	}
	d = lock->data;

	for (i = 0; i < d->num_share_modes; i++) {
		struct share_mode_entry *e = &d->share_modes[i];

		if (share_mode_stale_pid(d, i)) {
			continue;
		}

		if (e->private_options &
		    NTCREATEX_OPTIONS_PRIVATE_STREAM_BASEOPEN)
		{
			TALLOC_FREE(lock);
			return true;
		}
	}

	TALLOC_FREE(lock);
	return false;
}

/*
 * Walk share mode entries, looking at every lease only once
 */

bool share_mode_forall_leases(
	struct share_mode_lock *lck,
	bool (*fn)(struct share_mode_lock *lck,
		   struct share_mode_entry *e,
		   void *private_data),
	void *private_data)
{
	struct share_mode_data *d = lck->data;
	uint32_t *leases = NULL;
	uint32_t num_leases = 0;
	uint32_t i;

	leases = talloc_array(talloc_tos(), uint32_t, d->num_share_modes);
	if (leases == NULL) {
		return false;
	}

	for (i=0; i<d->num_share_modes; i++) {
		struct share_mode_entry *e = &d->share_modes[i];
		uint32_t j;
		bool ok, stop;

		ok = is_valid_share_mode_entry(e);
		if (!ok) {
			continue;
		}

		if (e->op_type != LEASE_OPLOCK) {
			continue;
		}

		/*
		 * See if we have already seen "e"'s lease. This is
		 * O(n^2). If we sort "leases", we can get this down
		 * to O(n).
		 */

		for (j=0; j<num_leases; j++) {
			uint32_t idx = leases[j];
			struct share_mode_entry *l = &d->share_modes[idx];

			if (smb2_lease_equal(&e->client_guid,
					     &e->lease_key,
					     &l->client_guid,
					     &l->lease_key)) {
				break;
			}
		}
		if (j < num_leases) {
			/*
			 * Don't look at "e"'s lease, we've already
			 * seen it.
			 */
			continue;
		}

		stop = fn(lck, e, private_data);
		if (stop) {
			TALLOC_FREE(leases);
			return true;
		}

		leases[num_leases] = i;
		num_leases += 1;
	}

	TALLOC_FREE(leases);
	return true;
}