openldap/servers/slapd/back-bdb/search.c

/* search.c - search operation */
/* $OpenLDAP$ */
/*
 * Copyright 1998-2003 The OpenLDAP Foundation, All Rights Reserved.
 * COPYING RESTRICTIONS APPLY, see COPYRIGHT file
 */

#include "portable.h"

#include <stdio.h>
#include <ac/string.h>

#include "back-bdb.h"
#include "idl.h"
#include "external.h"

static int base_candidate(
	BackendDB	*be,
	Entry	*e,
	ID		*ids );
static int search_candidates(
	Operation *stackop,	/* op with the current threadctx/slab cache */
	Operation *sop,		/* search op */
	SlapReply *rs,
	Entry *e,
	u_int32_t locker,
	ID	*ids,
	ID	*scopes );
static void send_pagerequest_response( 
	Operation *op,
	SlapReply *rs,
	ID  lastid,
	int tentries );

/* Dereference aliases for a single alias entry. Return the final
 * dereferenced entry on success, NULL on any failure.
 */
static Entry * deref_base (
	Operation *op,
	SlapReply *rs,
	Entry *e,
	Entry **matched,
	u_int32_t locker,
	DB_LOCK *lock,
	ID	*tmp,
	ID	*visited )
{
	struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;
	struct berval ndn;
	EntryInfo *ei;
	DB_LOCK lockr;

	rs->sr_err = LDAP_ALIAS_DEREF_PROBLEM;
	rs->sr_text = "maximum deref depth exceeded";

	while (BDB_IDL_N(tmp) < op->o_bd->be_max_deref_depth) {

		/* Remember the last entry we looked at, so we can
		 * report broken links
		 */
		*matched = e;

		/* If this is part of a subtree or onelevel search,
		 * have we seen this ID before? If so, quit.
		 */
		if ( visited && bdb_idl_insert( visited, e->e_id ) ) {
			e = NULL;
			break;
		}

		/* If we've seen this ID during this deref iteration,
		 * we've hit a loop.
		 */
		if ( bdb_idl_insert( tmp, e->e_id ) ) {
			rs->sr_err = LDAP_ALIAS_PROBLEM;
			rs->sr_text = "circular alias";
			e = NULL;
			break;
		}

		/* If there was a problem getting the aliasedObjectName,
		 * get_alias_dn will have set the error status.
		 */
		if ( get_alias_dn(e, &ndn, &rs->sr_err, &rs->sr_text) ) {
			e = NULL;
			break;
		}

		rs->sr_err = bdb_dn2entry( op, NULL, &ndn, &ei,
			0, locker, &lockr );

		if ( ei ) e = ei->bei_e;
		else	e = NULL;

		if (!e) {
			rs->sr_err = LDAP_ALIAS_PROBLEM;
			rs->sr_text = "aliasedObject not found";
			break;
		}

		/* Free the previous entry, continue to work with the
		 * one we just retrieved.
		 */
		bdb_cache_return_entry_r( bdb->bi_dbenv, &bdb->bi_cache,
			*matched, lock);
		*lock = lockr;

		/* We found a regular entry. Return this to the caller. The
		 * entry is still locked for Read.
		 */
		if (!is_entry_alias(e)) {
			rs->sr_err = LDAP_SUCCESS;
			rs->sr_text = NULL;
			break;
		}
	}
	return e;
}

/* Look for and dereference all aliases within the search scope. Adds
 * the dereferenced entries to the "ids" list. Requires "stack" to be
 * able to hold 8 levels of DB_SIZE IDLs. Of course we're hardcoded to
 * require a minimum of 8 UM_SIZE IDLs so this is never a problem.
 */
static int search_aliases(
	Operation *op,
	SlapReply *rs,
	Entry *e,
	u_int32_t locker,
	ID *ids,
	ID *scopes,
	ID *stack
)
{
	struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;
	ID *aliases, *curscop, *subscop, *visited, *newsubs, *oldsubs, *tmp;
	ID cursora, ida, cursoro, ido, *subscop2;
	Entry *matched, *a;
	EntryInfo *ei;
	struct berval bv_alias = { sizeof("alias")-1, "alias" };
	AttributeAssertion aa_alias;
	Filter	af;
	DB_LOCK locka, lockr;
	int first = 1;

	aliases = stack;	/* IDL of all aliases in the database */
	curscop = aliases + BDB_IDL_DB_SIZE;	/* Aliases in the current scope */
	subscop = curscop + BDB_IDL_DB_SIZE;	/* The current scope */
	visited = subscop + BDB_IDL_DB_SIZE;	/* IDs we've seen in this search */
	newsubs = visited + BDB_IDL_DB_SIZE;	/* New subtrees we've added */
	oldsubs = newsubs + BDB_IDL_DB_SIZE;	/* Subtrees added previously */
	tmp = oldsubs + BDB_IDL_DB_SIZE;	/* Scratch space for deref_base() */

	/* A copy of subscop, because subscop gets clobbered by
	 * the bdb_idl_union/intersection routines
	 */
	subscop2 = tmp + BDB_IDL_DB_SIZE;

	af.f_choice = LDAP_FILTER_EQUALITY;
	af.f_ava = &aa_alias;
	af.f_av_desc = slap_schema.si_ad_objectClass;
	af.f_av_value = bv_alias;
	af.f_next = NULL;

	/* Find all aliases in database */
	BDB_IDL_ZERO( aliases );
	rs->sr_err = bdb_filter_candidates( op, &af, aliases,
		curscop, visited );
	if (rs->sr_err != LDAP_SUCCESS) {
		return rs->sr_err;
	}
	oldsubs[0] = 1;
	oldsubs[1] = e->e_id;

	BDB_IDL_ZERO( ids );
	BDB_IDL_ZERO( visited );
	BDB_IDL_ZERO( newsubs );

	cursoro = 0;
	ido = bdb_idl_first( oldsubs, &cursoro );

	for (;;) {
		/* Set curscop to only the aliases in the current scope. Start with
		 * all the aliases, obtain the IDL for the current scope, and then
		 * get the intersection of these two IDLs. Add the current scope
		 * to the cumulative list of candidates.
		 */
		BDB_IDL_CPY( curscop, aliases );
		rs->sr_err = bdb_dn2idl( op, e, subscop,
					subscop2+BDB_IDL_DB_SIZE );
		if (first) {
			first = 0;
		} else {
			bdb_cache_return_entry_r (bdb->bi_dbenv, &bdb->bi_cache, e, &locka);
		}
		BDB_IDL_CPY(subscop2, subscop);
		rs->sr_err = bdb_idl_intersection(curscop, subscop);
		bdb_idl_union( ids, subscop2 );

		/* Dereference all of the aliases in the current scope. */
		cursora = 0;
		for (ida = bdb_idl_first(curscop, &cursora); ida != NOID;
			ida = bdb_idl_next(curscop, &cursora))
		{
			ei = NULL;
			rs->sr_err = bdb_cache_find_id(op, NULL,
				ida, &ei, 0, locker, &lockr );
			if (rs->sr_err != LDAP_SUCCESS) {
				continue;
			}
			a = ei->bei_e;

			/* This should only happen if the curscop IDL has maxed out and
			 * turned into a range that spans IDs indiscriminately
			 */
			if (!is_entry_alias(a)) {
				bdb_cache_return_entry_r (bdb->bi_dbenv, &bdb->bi_cache,
					a, &lockr);
				continue;
			}

			/* Actually dereference the alias */
			BDB_IDL_ZERO(tmp);
			a = deref_base( op, rs, a, &matched, locker, &lockr,
				tmp, visited );
			if (a) {
				/* If the target was not already in our current candidates,
				 * make note of it in the newsubs list. Also
				 * set it in the scopes list so that bdb_search
				 * can check it.
				 */
				if (bdb_idl_insert(ids, a->e_id) == 0) {
					bdb_idl_insert(newsubs, a->e_id);
					bdb_idl_insert(scopes, a->e_id);
				}
				bdb_cache_return_entry_r( bdb->bi_dbenv, &bdb->bi_cache,
					a, &lockr);

			} else if (matched) {
				/* Alias could not be dereferenced, or it deref'd to
				 * an ID we've already seen. Ignore it.
				 */
				bdb_cache_return_entry_r( bdb->bi_dbenv, &bdb->bi_cache,
					matched, &lockr );
				rs->sr_text = NULL;
			}
		}
		/* If this is a OneLevel search, we're done; oldsubs only had one
		 * ID in it. For a Subtree search, oldsubs may be a list of scope IDs.
		 */
		if (op->ors_scope != LDAP_SCOPE_SUBTREE) break;
nextido:
		ido = bdb_idl_next( oldsubs, &cursoro );
		
		/* If we're done processing the old scopes, did we add any new
		 * scopes in this iteration? If so, go back and do those now.
		 */
		if (ido == NOID) {
			if (BDB_IDL_IS_ZERO(newsubs)) break;
			BDB_IDL_CPY(oldsubs, newsubs);
			BDB_IDL_ZERO(newsubs);
			cursoro = 0;
			ido = bdb_idl_first( oldsubs, &cursoro );
		}

		/* Find the entry corresponding to the next scope. If it can't
		 * be found, ignore it and move on. This should never happen;
		 * we should never see the ID of an entry that doesn't exist.
		 * Set the name so that the scope's IDL can be retrieved.
		 */
		ei = NULL;
		rs->sr_err = bdb_cache_find_id(op, NULL, ido, &ei,
			0, locker, &locka );
		if (rs->sr_err != LDAP_SUCCESS) goto nextido;
		e = ei->bei_e;
	}
	return rs->sr_err;
}

static
int is_sync_protocol( Operation *op )
{
	if ( op->o_sync_mode & SLAP_SYNC_REFRESH_AND_PERSIST )
		return 1;
	return 0;
}
	
#define IS_BDB_REPLACE(type) (( type == LDAP_PSEARCH_BY_DELETE ) || \
	( type == LDAP_PSEARCH_BY_SCOPEOUT ))
#define IS_PSEARCH (op != sop)

int
bdb_abandon( Operation *op, SlapReply *rs )
{
	Operation	*ps_list;
	struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;

	LDAP_LIST_FOREACH ( ps_list, &bdb->bi_psearch_list, o_ps_link ) {
		if ( ps_list->o_connid == op->o_connid ) {
			if ( ps_list->o_msgid == op->oq_abandon.rs_msgid ) {
				ps_list->o_abandon = 1;
				LDAP_LIST_REMOVE( ps_list, o_ps_link );
				slap_op_free ( ps_list );
				return LDAP_SUCCESS;
			}
		}
	}
	return LDAP_UNAVAILABLE;
}

int
bdb_cancel( Operation *op, SlapReply *rs )
{
	Operation	*ps_list;
	struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;

	LDAP_LIST_FOREACH ( ps_list, &bdb->bi_psearch_list, o_ps_link ) {
		if ( ps_list->o_connid == op->o_connid ) {
			if ( ps_list->o_msgid == op->oq_cancel.rs_msgid ) {
				ps_list->o_cancel = SLAP_CANCEL_DONE;
				LDAP_LIST_REMOVE( ps_list, o_ps_link );

#if 0
				bdb_build_sync_done_ctrl( conn, ps_list, ps_list->ctrls,
					1, &latest_entrycsn_bv );
				send_ldap_result( conn, ps_list, LDAP_CANCELLED,
					NULL, NULL, NULL, ps_list->ctrls, ps_list->nentries);
#endif
				rs->sr_err = LDAP_CANCELLED;
				send_ldap_result( ps_list, rs );

				if ( ps_list->o_tmpmemctx ) {
					sl_mem_destroy( NULL, ps_list->o_tmpmemctx );
				}

				slap_op_free ( ps_list );
				return LDAP_SUCCESS;
			}
		}
	}
	return LDAP_UNAVAILABLE;
}

int bdb_search( Operation *op, SlapReply *rs )
{
	return bdb_do_search( op, rs, op, NULL, 0 );
}

/* For persistent searches, op is the currently executing operation,
 * sop is the persistent search. For regular searches, sop = op.
 */
int
bdb_do_search( Operation *op, SlapReply *rs, Operation *sop,
	Entry *ps_e, int ps_type )
{
	struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;
	time_t		stoptime;
	ID		id, cursor;
	ID		candidates[BDB_IDL_UM_SIZE];
	ID		scopes[BDB_IDL_DB_SIZE];
	Entry		*e = NULL, base;
	Entry	*matched = NULL;
	EntryInfo	*ei;
	struct berval	realbase = { 0, NULL };
	int		manageDSAit;
	int		tentries = 0;
	ID		lastid = NOID;
	AttributeName	*attrs;

	Filter 		contextcsnand, contextcsnle, cookief, csnfnot, csnfeq, csnfand, csnfge;
	Filter		omitcsnf, omitcsnfle;
	AttributeAssertion aa_ge, aa_eq, aa_le;
	int		entry_count = 0;
	struct berval *search_context_csn = NULL;
	struct berval ctxcsn_rdn = { 0, NULL };
	struct berval ctxcsn_ndn = { 0, NULL };
	EntryInfo	*ctxcsn_ei;
	Entry		*ctxcsn_e;
	DB_LOCK		ctxcsn_lock;
	Attribute	*csn_a;
#if 0
	struct berval	entrycsn_bv = { 0, NULL };
#endif
	LDAPControl	*ctrls[SLAP_SEARCH_MAX_CTRLS];
	int		num_ctrls = 0;
	AttributeName	uuid_attr[2];
	int		rc_sync = 0;
	int		entry_sync_state = -1;
	AttributeName	null_attr;
	int		no_sync_state_change = 0;
	struct slap_limits_set *limit = NULL;
	int isroot = 0;

	u_int32_t	locker = 0;
	DB_LOCK		lock;

#ifdef NEW_LOGGING
	LDAP_LOG( OPERATION, ENTRY, "bdb_back_search\n", 0, 0, 0 );
#else
	Debug( LDAP_DEBUG_TRACE, "=> bdb_back_search\n",
		0, 0, 0);
#endif
	attrs = sop->oq_search.rs_attrs;

	/* psearch needs to be registered before refresh begins */
	/* psearch and refresh transmission is serialized in send_ldap_ber() */
	if ( !IS_PSEARCH && sop->o_sync_mode & SLAP_SYNC_PERSIST ) {
		LDAP_LIST_INSERT_HEAD( &bdb->bi_psearch_list, sop, o_ps_link );
	}
	null_attr.an_desc = NULL;
	null_attr.an_oc = NULL;
	null_attr.an_name.bv_len = 0;
	null_attr.an_name.bv_val = NULL;

	for ( num_ctrls = 0; num_ctrls < SLAP_SEARCH_MAX_CTRLS; num_ctrls++ ) {
		ctrls[num_ctrls] = NULL;
	}
	num_ctrls = 0;

	if ( IS_PSEARCH && IS_BDB_REPLACE(ps_type)) {
		attrs = uuid_attr;
		attrs[0].an_desc = NULL;
		attrs[0].an_oc = NULL;
		attrs[0].an_name.bv_len = 0;
		attrs[0].an_name.bv_val = NULL;
	}

	manageDSAit = get_manageDSAit( sop );

	/* Sync control overrides manageDSAit */

	if ( !IS_PSEARCH && sop->o_sync_mode & SLAP_SYNC_REFRESH ) {
		if ( manageDSAit == SLAP_NO_CONTROL )
			manageDSAit = SLAP_CRITICAL_CONTROL;
	} else if ( IS_PSEARCH ) {
		if ( manageDSAit == SLAP_NO_CONTROL )
			manageDSAit = SLAP_CRITICAL_CONTROL;
	}

	rs->sr_err = LOCK_ID (bdb->bi_dbenv, &locker );

	switch(rs->sr_err) {
	case 0:
		break;
	default:
		send_ldap_error( sop, rs, LDAP_OTHER, "internal error" );
		return rs->sr_err;
	}

	if ( sop->o_req_ndn.bv_len == 0 ) {
		/* DIT root special case */
		e = (Entry *) &slap_entry_root;
		rs->sr_err = LDAP_SUCCESS;
	} else {
dn2entry_retry:
		/* get entry with reader lock */
		rs->sr_err = bdb_dn2entry( op, NULL, &sop->o_req_ndn, &ei,
			1, locker, &lock );
	}

	switch(rs->sr_err) {
	case DB_NOTFOUND:
		matched = ei->bei_e; break;
	case 0:
		e = ei->bei_e; break;
	case LDAP_BUSY:
		send_ldap_error( sop, rs, LDAP_BUSY, "ldap server busy" );
		LOCK_ID_FREE (bdb->bi_dbenv, locker );
		return LDAP_BUSY;
	case DB_LOCK_DEADLOCK:
	case DB_LOCK_NOTGRANTED:
		goto dn2entry_retry;
	default:
		send_ldap_error( sop, rs, LDAP_OTHER, "internal error" );
		LOCK_ID_FREE (bdb->bi_dbenv, locker );
		return rs->sr_err;
	}

	if ( e && (op->ors_deref & LDAP_DEREF_FINDING) && is_entry_alias(e) ) {
		BDB_IDL_ZERO(candidates);
		e = deref_base( op, rs, e, &matched, locker, &lock,
			candidates, NULL );
	}

	if ( e == NULL ) {
		struct berval matched_dn = { 0, NULL };

		if ( matched != NULL ) {
			BerVarray erefs;
			ber_dupbv( &matched_dn, &matched->e_name );

			erefs = is_entry_referral( matched )
				? get_entry_referrals( op, matched )
				: NULL;

			bdb_cache_return_entry_r (bdb->bi_dbenv, &bdb->bi_cache,
				matched, &lock);
			matched = NULL;

			if( erefs ) {
				rs->sr_ref = referral_rewrite( erefs, &matched_dn,
					&sop->o_req_dn, sop->oq_search.rs_scope );
				ber_bvarray_free( erefs );
			}

		} else {
			rs->sr_ref = referral_rewrite( default_referral,
				NULL, &sop->o_req_dn, sop->oq_search.rs_scope );
		}

		rs->sr_err = LDAP_REFERRAL;
		rs->sr_matched = matched_dn.bv_val;
		send_ldap_result( sop, rs );

		LOCK_ID_FREE (bdb->bi_dbenv, locker );
		if ( rs->sr_ref ) {
			ber_bvarray_free( rs->sr_ref );
			rs->sr_ref = NULL;
		}
		if ( matched_dn.bv_val ) {
			ber_memfree( matched_dn.bv_val );
			rs->sr_matched = NULL;
		}
		return rs->sr_err;
	}

	if (!manageDSAit && e != &slap_entry_root && is_entry_referral( e ) ) {
		/* entry is a referral, don't allow add */
		struct berval matched_dn;
		BerVarray erefs;
		
		ber_dupbv( &matched_dn, &e->e_name );
		erefs = get_entry_referrals( op, e );

		bdb_cache_return_entry_r( bdb->bi_dbenv, &bdb->bi_cache, e, &lock );
		e = NULL;

		if( erefs ) {
			rs->sr_ref = referral_rewrite( erefs, &matched_dn,
				&sop->o_req_dn, sop->oq_search.rs_scope );
			ber_bvarray_free( erefs );
		}

#ifdef NEW_LOGGING
		LDAP_LOG ( OPERATION, RESULTS, 
			"bdb_search: entry is referral\n", 0, 0, 0 );
#else
		Debug( LDAP_DEBUG_TRACE, "bdb_search: entry is referral\n",
			0, 0, 0 );
#endif

		if (!rs->sr_ref) rs->sr_text = "bad_referral object";
		rs->sr_err = LDAP_REFERRAL;
		rs->sr_matched = matched_dn.bv_val;
		send_ldap_result( sop, rs );

		LOCK_ID_FREE (bdb->bi_dbenv, locker );
		ber_bvarray_free( rs->sr_ref );
		rs->sr_ref = NULL;
		ber_memfree( matched_dn.bv_val );
		rs->sr_matched = NULL;
		return 1;
	}

	if ( get_assert( op ) &&
		( test_filter( op, e, get_assertion( op )) != LDAP_COMPARE_TRUE ))
	{
		rs->sr_err = LDAP_ASSERTION_FAILED;
		send_ldap_result( sop, rs );
		return 1;
	}

	/* if not root, get appropriate limits */
	if ( be_isroot( op->o_bd, &sop->o_ndn ) ) {
		isroot = 1;
	} else {
		( void ) get_limits( op->o_bd, &sop->o_ndn, &limit );
	}

	/* The time/size limits come first because they require very little
	 * effort, so there's no chance the candidates are selected and then 
	 * the request is not honored only because of time/size constraints */

	/* if no time limit requested, use soft limit (unless root!) */
	if ( isroot ) {
		if ( sop->oq_search.rs_tlimit == 0 ) {
			sop->oq_search.rs_tlimit = -1;	/* allow root to set no limit */
		}

		if ( sop->oq_search.rs_slimit == 0 ) {
			sop->oq_search.rs_slimit = -1;
		}

	} else {
		/* if no limit is required, use soft limit */
		if ( sop->oq_search.rs_tlimit <= 0 ) {
			sop->oq_search.rs_tlimit = limit->lms_t_soft;

		/* if requested limit higher than hard limit, abort */
		} else if ( sop->oq_search.rs_tlimit > limit->lms_t_hard ) {
			/* no hard limit means use soft instead */
			if ( limit->lms_t_hard == 0
					&& limit->lms_t_soft > -1
					&& sop->oq_search.rs_tlimit > limit->lms_t_soft ) {
				sop->oq_search.rs_tlimit = limit->lms_t_soft;

			/* positive hard limit means abort */
			} else if ( limit->lms_t_hard > 0 ) {
				rs->sr_err = LDAP_ADMINLIMIT_EXCEEDED;
				send_ldap_result( sop, rs );
				rs->sr_err = LDAP_SUCCESS;
				goto done;
			}
		
			/* negative hard limit means no limit */
		}
		
		/* if no limit is required, use soft limit */
		if ( sop->oq_search.rs_slimit <= 0 ) {
			if ( get_pagedresults(sop) && limit->lms_s_pr != 0 ) {
				sop->oq_search.rs_slimit = limit->lms_s_pr;
			} else {
				sop->oq_search.rs_slimit = limit->lms_s_soft;
			}

		/* if requested limit higher than hard limit, abort */
		} else if ( sop->oq_search.rs_slimit > limit->lms_s_hard ) {
			/* no hard limit means use soft instead */
			if ( limit->lms_s_hard == 0
					&& limit->lms_s_soft > -1
					&& sop->oq_search.rs_slimit > limit->lms_s_soft ) {
				sop->oq_search.rs_slimit = limit->lms_s_soft;

			/* positive hard limit means abort */
			} else if ( limit->lms_s_hard > 0 ) {
				rs->sr_err = LDAP_ADMINLIMIT_EXCEEDED;
				send_ldap_result( sop, rs );
				rs->sr_err = LDAP_SUCCESS;	
				goto done;
			}
			
			/* negative hard limit means no limit */
		}
	}

	/* compute it anyway; root does not use it */
	stoptime = op->o_time + sop->oq_search.rs_tlimit;

	/* need normalized dn below */
	ber_dupbv( &realbase, &e->e_nname );

	/* Copy info to base, must free entry before accessing the database
	 * in search_candidates, to avoid deadlocks.
	 */
	base.e_private = e->e_private;
	base.e_nname = realbase;
	base.e_id = e->e_id;

	if ( e != &slap_entry_root ) {
		bdb_cache_return_entry_r(bdb->bi_dbenv, &bdb->bi_cache, e, &lock);
	}
	e = NULL;

	if ( sop->o_sync_mode != SLAP_SYNC_NONE ) {
		if ( sop->o_bd->syncinfo ) {
			char substr[67];
			sprintf( substr, "cn=syncrepl%d", sop->o_bd->syncinfo->id );
			ber_str2bv( substr, strlen( substr ), 0, &ctxcsn_rdn );
			build_new_dn( &ctxcsn_ndn, &op->o_bd->be_nsuffix[0], &ctxcsn_rdn );
		} else {
			ber_str2bv( "cn=ldapsync", strlen("cn=ldapsync"), 0, &ctxcsn_rdn );
			build_new_dn( &ctxcsn_ndn, &op->o_bd->be_nsuffix[0], &ctxcsn_rdn );
		}

ctxcsn_retry :
		rs->sr_err = bdb_dn2entry( op, NULL, &ctxcsn_ndn, &ctxcsn_ei, 0, locker, &ctxcsn_lock );

		switch(rs->sr_err) {
		case 0:
			e = ei->bei_e; break;
		case LDAP_BUSY:
			send_ldap_error( sop, rs, LDAP_BUSY, "ldap server busy" );
			LOCK_ID_FREE (bdb->bi_dbenv, locker );
			return LDAP_BUSY;
		case DB_LOCK_DEADLOCK:
		case DB_LOCK_NOTGRANTED:
			goto ctxcsn_retry;
		case DB_NOTFOUND:
			send_ldap_error( sop, rs, LDAP_OTHER, "context csn entry not present" );
			LOCK_ID_FREE( bdb->bi_dbenv, locker );
			return rs->sr_err;
		default:
			send_ldap_error( sop, rs, LDAP_OTHER, "internal error" );
			LOCK_ID_FREE (bdb->bi_dbenv, locker );
			return rs->sr_err;
		}

		if ( ctxcsn_ei ) {
			ctxcsn_e = ctxcsn_ei->bei_e;
		}

		if ( ctxcsn_e ) {
			if ( sop->o_bd->syncinfo ) {
				csn_a = attr_find( ctxcsn_e->e_attrs, slap_schema.si_ad_syncreplCookie );
			} else {
				csn_a = attr_find( ctxcsn_e->e_attrs, slap_schema.si_ad_contextCSN );
			}
			if ( csn_a ) {
				search_context_csn = ber_dupbv( NULL, &csn_a->a_vals[0] );
			} else {
				search_context_csn = NULL;
			}
		} else {
			search_context_csn = NULL;
		}
	}

	/* select candidates */
	if ( sop->oq_search.rs_scope == LDAP_SCOPE_BASE ) {
		rs->sr_err = base_candidate( op->o_bd, &base, candidates );

	} else {
		BDB_IDL_ZERO( candidates );
		BDB_IDL_ZERO( scopes );
		rs->sr_err = search_candidates( op, sop, rs, &base, locker, candidates, scopes );
	}

	if ( sop->o_sync_mode != SLAP_SYNC_NONE ) {
		bdb_cache_entry_db_unlock( bdb->bi_dbenv, &ctxcsn_lock );
	}

	/* start cursor at beginning of candidates.
	 */
	cursor = 0;
	if (IS_PSEARCH) {
		if ( !BDB_IDL_IS_RANGE( candidates ) ) {
			cursor = bdb_idl_search( candidates, ps_e->e_id );
			if ( candidates[cursor] != ps_e->e_id ) {
			   	rs->sr_err = LDAP_SUCCESS;
			   	goto done;
			}
		} else {
			if ( ps_e->e_id < BDB_IDL_RANGE_FIRST(candidates)
			   || ps_e->e_id > BDB_IDL_RANGE_LAST(candidates)){
			   	rs->sr_err = LDAP_SUCCESS;
			   	goto done;
			}
		}
		candidates[0] = 1;
		candidates[1] = ps_e->e_id;
	}

	if ( candidates[0] == 0 ) {
#ifdef NEW_LOGGING
		LDAP_LOG ( OPERATION, RESULTS,
			"bdb_search: no candidates\n", 0, 0, 0 );
#else
		Debug( LDAP_DEBUG_TRACE, "bdb_search: no candidates\n",
			0, 0, 0 );
#endif

		rs->sr_err = LDAP_SUCCESS;
		rs->sr_entry = NULL;
		send_ldap_result( sop, rs );
		goto done;
	}

	/* if not root and candidates exceed to-be-checked entries, abort */
	if ( !isroot && limit->lms_s_unchecked != -1 ) {
		if ( BDB_IDL_N(candidates) > (unsigned) limit->lms_s_unchecked ) {
			rs->sr_err = LDAP_ADMINLIMIT_EXCEEDED;
			send_ldap_result( sop, rs );
			rs->sr_err = LDAP_SUCCESS;
			goto done;
		}
	}

	if ( isroot || !limit->lms_s_pr_hide ) {
		tentries = BDB_IDL_N(candidates);
	}

#ifdef LDAP_CONTROL_PAGEDRESULTS
	if ( get_pagedresults(sop) ) {
		if ( sop->o_pagedresults_state.ps_cookie == 0 ) {
			id = 0;
		} else {
			if ( sop->o_pagedresults_size == 0 ) {
				rs->sr_err = LDAP_SUCCESS;
				rs->sr_text = "search abandoned by pagedResult size=0";
				send_ldap_result( sop, rs );
				goto done;
			}
			for ( id = bdb_idl_first( candidates, &cursor );
				id != NOID && id <= (ID)( sop->o_pagedresults_state.ps_cookie );
				id = bdb_idl_next( candidates, &cursor ) );
		}
		if ( cursor == NOID ) {
#ifdef NEW_LOGGING
			LDAP_LOG ( OPERATION, RESULTS, 
				"bdb_search: no paged results candidates\n", 
			0, 0, 0 );
#else
			Debug( LDAP_DEBUG_TRACE, 
				"bdb_search: no paged results candidates\n",
				0, 0, 0 );
#endif
			send_pagerequest_response( sop, rs, lastid, 0 );

			rs->sr_err = LDAP_OTHER;
			goto done;
		}
		goto loop_begin;
	}
#endif

	if ( (sop->o_sync_mode & SLAP_SYNC_REFRESH) || IS_PSEARCH )
	{
		MatchingRule	*mr;
		const char		*text;
		int				match;

		cookief.f_choice = LDAP_FILTER_AND;
		cookief.f_and = &csnfnot;
		cookief.f_next = NULL;

		csnfnot.f_choice = LDAP_FILTER_NOT;
		csnfnot.f_not = &csnfeq;
		csnfnot.f_next = &csnfand;

		csnfeq.f_choice = LDAP_FILTER_EQUALITY;
		csnfeq.f_ava = &aa_eq;
		csnfeq.f_av_desc = slap_schema.si_ad_entryCSN;
		csnfeq.f_av_value = sop->o_sync_state;

		csnfand.f_choice = LDAP_FILTER_AND;
		csnfand.f_and = &csnfge;
		csnfand.f_next = NULL;

		csnfge.f_choice = LDAP_FILTER_GE;
		csnfge.f_ava = &aa_ge;
		csnfge.f_av_desc = slap_schema.si_ad_entryCSN;
		csnfge.f_av_value = sop->o_sync_state;

		if ( search_context_csn && !IS_PSEARCH ) {
			csnfge.f_next = &contextcsnand;

			contextcsnand.f_choice = LDAP_FILTER_AND;
			contextcsnand.f_and = &contextcsnle;
			contextcsnand.f_next = NULL;
	
			contextcsnle.f_choice = LDAP_FILTER_LE;
			contextcsnle.f_ava = &aa_le;
			contextcsnle.f_av_desc = slap_schema.si_ad_entryCSN;
			contextcsnle.f_av_value = *search_context_csn;
			contextcsnle.f_next = sop->oq_search.rs_filter;

			mr = slap_schema.si_ad_entryCSN->ad_type->sat_ordering;
			if ( sop->o_sync_state.bv_len != 0 ) {
				value_match( &match, slap_schema.si_ad_entryCSN, mr,
							SLAP_MR_VALUE_OF_ATTRIBUTE_SYNTAX,
							&sop->o_sync_state, search_context_csn, &text );
			} else {
				match = -1;
			}
			no_sync_state_change = !match;
		} else {
			csnfge.f_next = sop->oq_search.rs_filter;
		}
	}

	for ( id = bdb_idl_first( candidates, &cursor );
		id != NOID;
		id = bdb_idl_next( candidates, &cursor ) )
	{
		int		scopeok = 0;

loop_begin:
		/* check for abandon */
		if ( sop->o_abandon ) {
			rs->sr_err = LDAP_SUCCESS;
			goto done;
		}

#ifdef LDAP_EXOP_X_CANCEL
		if ( sop->o_cancel ) {
			assert( sop->o_cancel == SLAP_CANCEL_REQ );
			rs->sr_err = LDAP_CANCELLED;
			send_ldap_result( sop, rs );
			sop->o_cancel = SLAP_CANCEL_ACK;
			rs->sr_err = LDAP_SUCCESS;
			goto done;
		}
#endif

		/* check time limit */
		if ( sop->oq_search.rs_tlimit != -1 && slap_get_time() > stoptime ) {
			rs->sr_err = LDAP_TIMELIMIT_EXCEEDED;
			rs->sr_ref = rs->sr_v2ref;
			send_ldap_result( sop, rs );
			rs->sr_err = LDAP_SUCCESS;
			goto done;
		}


		if (!IS_PSEARCH) {
id2entry_retry:
			/* get the entry with reader lock */
			ei = NULL;
			rs->sr_err = bdb_cache_find_id( op, NULL,
				id, &ei, 0, locker, &lock );

			if (rs->sr_err == LDAP_BUSY) {
				rs->sr_text = "ldap server busy";
				send_ldap_result( sop, rs );
				goto done;

			} else if ( rs->sr_err == DB_LOCK_DEADLOCK
				|| rs->sr_err == DB_LOCK_NOTGRANTED )
			{
				goto id2entry_retry;	
			}

			if ( ei && rs->sr_err == LDAP_SUCCESS ) {
				e = ei->bei_e;
			} else {
				e = NULL;
			}

			if ( e == NULL ) {
				if( !BDB_IDL_IS_RANGE(candidates) ) {
					/* only complain for non-range IDLs */
#ifdef NEW_LOGGING
					LDAP_LOG ( OPERATION, RESULTS,
						"bdb_search: candidate %ld not found\n",
						(long) id, 0, 0);
#else
					Debug( LDAP_DEBUG_TRACE,
						"bdb_search: candidate %ld not found\n",
						(long) id, 0, 0 );
#endif
				}

				goto loop_continue;
			}
		} else {
			e = ps_e;
		}

		rs->sr_entry = e;
#ifdef BDB_SUBENTRIES
		/* FIXME: send all but syncrepl
		if ( !is_sync_protocol( sop ) ) {
		*/
			if ( is_entry_subentry( e ) ) {
				if( sop->oq_search.rs_scope != LDAP_SCOPE_BASE ) {
					if(!get_subentries_visibility( sop )) {
						/* only subentries are visible */
						goto loop_continue;
					}

				} else if ( get_subentries( sop ) &&
					!get_subentries_visibility( sop ))
				{
					/* only subentries are visible */
					goto loop_continue;
				}

			} else if ( get_subentries_visibility( sop )) {
				/* only subentries are visible */
				goto loop_continue;
			}
		/*
		}
		*/
#endif

		/* Does this candidate actually satisfy the search scope?
		 *
		 * Note that we don't lock access to the bei_parent pointer.
		 * Since only leaf nodes can be deleted, the parent of any
		 * node will always be a valid node. Also since we have
		 * a Read lock on the data, it cannot be renamed out of the
		 * scope while we are looking at it, and unless we're using
		 * BDB_HIER, its parents cannot be moved either.
		 */
		switch( sop->ors_scope ) {
		case LDAP_SCOPE_BASE:
			/* This is always true, yes? */
			if ( id == base.e_id )
				scopeok = 1;
			break;
		case LDAP_SCOPE_ONELEVEL:
			if ( ei->bei_parent->bei_id == base.e_id )
				scopeok = 1;
			break;
		case LDAP_SCOPE_SUBTREE:
			{ EntryInfo *tmp;
			for ( tmp = BEI(e); tmp->bei_parent;
				tmp = tmp->bei_parent ) {
				if ( tmp->bei_id == base.e_id ) {
					scopeok = 1;
					break;
				}
			} }
			break;
		}

#ifdef BDB_ALIASES
		/* aliases were already dereferenced in candidate list */
		if ( sop->ors_deref & LDAP_DEREF_SEARCHING ) {
			/* but if the search base is an alias, and we didn't
			 * deref it when finding, return it.
			 */
			if ( is_entry_alias(e) &&
				((sop->ors_deref & LDAP_DEREF_FINDING)
				  || !bvmatch(&e->e_nname, &op->o_req_ndn)))
			{
				goto loop_continue;
			}

			/* scopes is only non-empty for onelevel or subtree */
			if ( !scopeok && BDB_IDL_N(scopes) ) {
				unsigned x;
				if ( sop->ors_scope == LDAP_SCOPE_ONELEVEL ) {
					x = bdb_idl_search( scopes,
						e->e_id );
					if ( scopes[x] == e->e_id )
						scopeok = 1;
				} else {
				/* subtree, walk up the tree */
					EntryInfo *tmp = BEI(e);
					for (;tmp->bei_parent;
						tmp=tmp->bei_parent) {
						x = bdb_idl_search(
							scopes, tmp->bei_id );
						if ( scopes[x] == tmp->bei_id ) {
							scopeok = 1;
							break;
						}
					}
				}
			}
		}
#endif

		/* Not in scope, ignore it */
		if ( !scopeok ) {
#ifdef NEW_LOGGING
			LDAP_LOG ( OPERATION, RESULTS,
				"bdb_search: %ld scope not okay\n",
				(long) id, 0, 0);
#else
			Debug( LDAP_DEBUG_TRACE,
				"bdb_search: %ld scope not okay\n",
				(long) id, 0, 0 );
#endif
			goto loop_continue;
		}

		/*
		 * if it's a referral, add it to the list of referrals. only do
		 * this for non-base searches, and don't check the filter
		 * explicitly here since it's only a candidate anyway.
		 */
		if ( !manageDSAit && sop->oq_search.rs_scope != LDAP_SCOPE_BASE
			&& is_entry_referral( e ) )
		{
			BerVarray erefs = get_entry_referrals( sop, e );
			rs->sr_ref = referral_rewrite( erefs,
				&e->e_name, NULL,
				sop->oq_search.rs_scope == LDAP_SCOPE_SUBTREE
					? LDAP_SCOPE_SUBTREE
					: LDAP_SCOPE_BASE );

			send_search_reference( sop, rs );

			ber_bvarray_free( rs->sr_ref );
			ber_bvarray_free( erefs );
			rs->sr_ref = NULL;

			goto loop_continue;
		}

		if ( !manageDSAit && is_entry_glue( e )) {
			goto loop_continue;
		}

		/* if it matches the filter and scope, send it */
		if (IS_PSEARCH) {
			if (ps_type != LDAP_PSEARCH_BY_SCOPEOUT) {
				rs->sr_err = test_filter( sop, rs->sr_entry, &cookief );
			} else {
				rs->sr_err = LDAP_COMPARE_TRUE;
			}
		} else {
			if ( sop->o_sync_mode & SLAP_SYNC_REFRESH ) {
				rc_sync = test_filter( sop, rs->sr_entry, &cookief );
				rs->sr_err = test_filter( sop,
					rs->sr_entry, &contextcsnand );
				if ( rs->sr_err == LDAP_COMPARE_TRUE ) {
					if ( rc_sync == LDAP_COMPARE_TRUE ) {
						if ( no_sync_state_change ) {
#ifdef NEW_LOGGING
							LDAP_LOG ( OPERATION, RESULTS,
								"bdb_search: error in context csn management\n",
								0, 0, 0 );
#else
							Debug( LDAP_DEBUG_TRACE,
								"bdb_search: error in context csn management\n",
								0, 0, 0 );
#endif
						}
						entry_sync_state = LDAP_SYNC_ADD;
					} else {
						if ( no_sync_state_change ) {
							goto loop_continue;
						}
						entry_sync_state = LDAP_SYNC_PRESENT;
					}
				}
			} else {
				rs->sr_err = test_filter( sop,
					rs->sr_entry, sop->oq_search.rs_filter );
			}
		}

		if ( rs->sr_err == LDAP_COMPARE_TRUE ) {
			/* check size limit */
			if ( --sop->oq_search.rs_slimit == -1 ) {
				if (!IS_PSEARCH) {
					bdb_cache_return_entry_r( bdb->bi_dbenv,
						&bdb->bi_cache, e, &lock );
				}
				e = NULL;
				rs->sr_entry = NULL;
				rs->sr_err = LDAP_SIZELIMIT_EXCEEDED;
				rs->sr_ref = rs->sr_v2ref;
				send_ldap_result( sop, rs );
				rs->sr_err = LDAP_SUCCESS;
				goto done;
			}

#ifdef LDAP_CONTROL_PAGEDRESULTS
			if ( get_pagedresults(sop) ) {
				if ( rs->sr_nentries >= sop->o_pagedresults_size ) {
					send_pagerequest_response( sop, rs,
						lastid, tentries );
					goto done;
				}
				lastid = id;
			}
#endif

			if (e) {
				/* safe default */
				int result = -1;
				
#if 0	/* noop is masked SLAP_CTRL_UPDATE */
				if( op->o_noop ) {
					result = 0;
				} else
#endif
				if (IS_PSEARCH) {
					int premodify_found = 0;
					int entry_sync_state;

					if ( ps_type == LDAP_PSEARCH_BY_ADD ||
						 ps_type == LDAP_PSEARCH_BY_DELETE ||
						 ps_type == LDAP_PSEARCH_BY_MODIFY ||
						 ps_type == LDAP_PSEARCH_BY_SCOPEOUT )
					{
						if ( ps_type == LDAP_PSEARCH_BY_MODIFY ) {
							struct psid_entry* psid_e;
							LDAP_LIST_FOREACH( psid_e,
								&op->o_pm_list, ps_link)
							{
								if( psid_e->ps_op == sop ) {
									premodify_found = 1;
									LDAP_LIST_REMOVE(psid_e, ps_link);
									break;
								}
							}
							if (psid_e != NULL) free (psid_e);
						}
						if ( ps_type == LDAP_PSEARCH_BY_ADD ) {
							entry_sync_state = LDAP_SYNC_ADD;
						} else if ( ps_type == LDAP_PSEARCH_BY_DELETE ) {
							entry_sync_state = LDAP_SYNC_DELETE;
						} else if ( ps_type == LDAP_PSEARCH_BY_MODIFY ) {
							if ( premodify_found ) {
								entry_sync_state = LDAP_SYNC_MODIFY;
							} else {
								entry_sync_state = LDAP_SYNC_ADD;
							}
						} else if ( ps_type == LDAP_PSEARCH_BY_SCOPEOUT )
							entry_sync_state = LDAP_SYNC_DELETE;
						else {
							rs->sr_err = LDAP_OTHER;
							goto done;
						}
						rs->sr_err = bdb_build_sync_state_ctrl( sop,
							rs, e, entry_sync_state, ctrls,
							num_ctrls++, 1, search_context_csn );
						if ( rs->sr_err != LDAP_SUCCESS ) goto done;
						rs->sr_attrs = attrs;
						rs->sr_ctrls = ctrls;
						result = send_search_entry( sop, rs );
						ch_free( ctrls[num_ctrls-1]->ldctl_value.bv_val );
						ch_free( ctrls[--num_ctrls] );
						ctrls[num_ctrls] = NULL;
						rs->sr_ctrls = NULL;

					} else if ( ps_type == LDAP_PSEARCH_BY_PREMODIFY ) {
						struct psid_entry* psid_e;
						psid_e = (struct psid_entry *) calloc (1,
							sizeof(struct psid_entry));
						psid_e->ps_op = sop;
						LDAP_LIST_INSERT_HEAD( &op->o_pm_list,
							psid_e, ps_link );

					} else {
						printf("Error !\n");
					}
				} else {
					if ( sop->o_sync_mode & SLAP_SYNC_REFRESH ) {
						rs->sr_err = bdb_build_sync_state_ctrl( sop,
							rs, e, entry_sync_state, ctrls,
							num_ctrls++, 0, search_context_csn );
						if ( rs->sr_err != LDAP_SUCCESS ) goto done;

						rs->sr_ctrls = ctrls;
						if ( rc_sync == LDAP_COMPARE_TRUE ) { /* ADD */
							rs->sr_attrs = sop->oq_search.rs_attrs;
						} else { /* PRESENT */
							rs->sr_attrs = &null_attr;
						}
						result = send_search_entry( sop, rs );
						ch_free( ctrls[num_ctrls-1]->ldctl_value.bv_val );
						ch_free( ctrls[--num_ctrls] );
						ctrls[num_ctrls] = NULL;
						rs->sr_ctrls = NULL;
					} else {
						rs->sr_attrs = sop->oq_search.rs_attrs;
						rs->sr_ctrls = NULL;
						result = send_search_entry( sop, rs );
					}
				}

				switch (result) {
				case 0:		/* entry sent ok */
					break;
				case 1:		/* entry not sent */
					break;
				case -1:	/* connection closed */
					if (!IS_PSEARCH)
					bdb_cache_return_entry_r(bdb->bi_dbenv,
						&bdb->bi_cache, e, &lock);
					e = NULL;
					rs->sr_entry = NULL;
					rs->sr_err = LDAP_OTHER;
					goto done;
				}
			}
		} else {
#ifdef NEW_LOGGING
			LDAP_LOG ( OPERATION, RESULTS,
				"bdb_search: %ld does not match filter\n", (long) id, 0, 0);
#else
			Debug( LDAP_DEBUG_TRACE,
				"bdb_search: %ld does not match filter\n",
				(long) id, 0, 0 );
#endif
		}

loop_continue:
		if( e != NULL ) {
			/* free reader lock */
			if (!IS_PSEARCH) {
				bdb_cache_return_entry_r( bdb->bi_dbenv,
					&bdb->bi_cache, e , &lock);
			}
			e = NULL;
			rs->sr_entry = NULL;
		}

		ldap_pvt_thread_yield();
	}

	if (!IS_PSEARCH) {
		if ( sop->o_sync_mode & SLAP_SYNC_REFRESH ) {
			rs->sr_err = LDAP_SUCCESS;
			rs->sr_rspoid = LDAP_SYNC_INFO;
			rs->sr_ctrls = NULL;
			bdb_send_ldap_intermediate( sop, rs,
				LDAP_SYNC_STATE_MODE_DONE, search_context_csn );

			/* If changelog is supported, this is where to process it */
	
			if ( sop->o_sync_mode & SLAP_SYNC_PERSIST ) {
				/* refreshAndPersist mode */
				bdb_send_ldap_intermediate( sop, rs,
					LDAP_SYNC_LOG_MODE_DONE, search_context_csn );
			} else {
				/* refreshOnly mode */
				bdb_build_sync_done_ctrl( sop, rs, ctrls,
					num_ctrls++, 1, search_context_csn );
				rs->sr_ctrls = ctrls;
				rs->sr_ref = rs->sr_v2ref;
				rs->sr_err = (rs->sr_v2ref == NULL) ? LDAP_SUCCESS : LDAP_REFERRAL;
				send_ldap_result( sop, rs );
				if ( ctrls[num_ctrls-1]->ldctl_value.bv_val != NULL ) {
					ch_free( ctrls[num_ctrls-1]->ldctl_value.bv_val );
				}
				ch_free( ctrls[--num_ctrls] );
				ctrls[num_ctrls] = NULL;
			}
		} else {
			rs->sr_ctrls = NULL;
			rs->sr_ref = rs->sr_v2ref;
			rs->sr_err = (rs->sr_v2ref == NULL) ? LDAP_SUCCESS : LDAP_REFERRAL;
			send_ldap_result( sop, rs );
		}
	}

	rs->sr_err = LDAP_SUCCESS;

done:
	if( !IS_PSEARCH && e != NULL ) {
		/* free reader lock */
		bdb_cache_return_entry_r ( bdb->bi_dbenv, &bdb->bi_cache, e, &lock );
	}

	LOCK_ID_FREE (bdb->bi_dbenv, locker );

	if( rs->sr_v2ref ) {
		ber_bvarray_free( rs->sr_v2ref );
		rs->sr_v2ref = NULL;
	}
	if( realbase.bv_val ) ch_free( realbase.bv_val );

	return rs->sr_err;
}


static int base_candidate(
	BackendDB	*be,
	Entry	*e,
	ID		*ids )
{
#ifdef NEW_LOGGING
	LDAP_LOG ( OPERATION, ENTRY,
		"base_candidate: base: \"%s\" (0x%08lx)\n",
		e->e_nname.bv_val, (long) e->e_id, 0);
#else
	Debug(LDAP_DEBUG_ARGS, "base_candidates: base: \"%s\" (0x%08lx)\n",
		e->e_nname.bv_val, (long) e->e_id, 0);
#endif

	ids[0] = 1;
	ids[1] = e->e_id;
	return 0;
}

/* Look for "objectClass Present" in this filter.
 * Also count depth of filter tree while we're at it.
 */
static int oc_filter(
	Filter *f,
	int cur,
	int *max
)
{
	int rc = 0;

	if( cur > *max ) *max = cur;

	switch(f->f_choice) {
	case LDAP_FILTER_PRESENT:
		if (f->f_desc == slap_schema.si_ad_objectClass) {
			rc = 1;
		}
		break;

	case LDAP_FILTER_AND:
	case LDAP_FILTER_OR:
		cur++;
		for (f=f->f_and; f; f=f->f_next) {
			(void) oc_filter(f, cur, max);
		}
		break;

	default:
		break;
	}
	return rc;
}

static void search_stack_free( void *key, void *data )
{
	ber_memfree_x(data, NULL);
}

static void *search_stack(
	Operation *op
)
{
	struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;
	void *ret = NULL;

	if ( op->o_threadctx ) {
		ldap_pvt_thread_pool_getkey( op->o_threadctx, search_stack,
			&ret, NULL );
	} else {
		ret = bdb->bi_search_stack;
	}

	if ( !ret ) {
		ret = ch_malloc( bdb->bi_search_stack_depth * BDB_IDL_UM_SIZE
			* sizeof( ID ) );
		if ( op->o_threadctx ) {
			ldap_pvt_thread_pool_setkey( op->o_threadctx, search_stack,
				ret, search_stack_free );
		} else {
			bdb->bi_search_stack = ret;
		}
	}
	return ret;
}

static int search_candidates(
	Operation *stackop,
	Operation *op,
	SlapReply *rs,
	Entry *e,
	u_int32_t locker,
	ID	*ids,
	ID	*scopes )
{
	struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;
	int rc, depth = 1;
	Filter		f, rf, xf, nf;
	ID		*stack;
	AttributeAssertion aa_ref;
#ifdef BDB_SUBENTRIES
	Filter	sf;
	AttributeAssertion aa_subentry;
#endif

	/*
	 * This routine takes as input a filter (user-filter)
	 * and rewrites it as follows:
	 *	(&(scope=DN)[(objectClass=subentry)]
	 *		(|[(objectClass=referral)(objectClass=alias)](user-filter))
	 */

#ifdef NEW_LOGGING
	LDAP_LOG ( OPERATION, ENTRY,
		"search_candidates: base=\"%s\" (0x%08lx) scope=%d\n", 
		e->e_nname.bv_val, (long) e->e_id, op->oq_search.rs_scope);
#else
	Debug(LDAP_DEBUG_TRACE,
		"search_candidates: base=\"%s\" (0x%08lx) scope=%d\n",
		e->e_nname.bv_val, (long) e->e_id, op->oq_search.rs_scope );
#endif

	xf.f_or = op->oq_search.rs_filter;
	xf.f_choice = LDAP_FILTER_OR;
	xf.f_next = NULL;

	/* If the user's filter uses objectClass=*,
	 * these clauses are redundant.
	 */
	if (!oc_filter(op->oq_search.rs_filter, 1, &depth)
		&& !get_subentries_visibility(op)
		&& !is_sync_protocol(op) )
	{
		if( !get_manageDSAit(op) && !get_domainScope(op) ) {
			/* match referral objects */
			struct berval bv_ref = { sizeof("referral")-1, "referral" };
			rf.f_choice = LDAP_FILTER_EQUALITY;
			rf.f_ava = &aa_ref;
			rf.f_av_desc = slap_schema.si_ad_objectClass;
			rf.f_av_value = bv_ref;
			rf.f_next = xf.f_or;
			xf.f_or = &rf;
			depth++;
		}
	}

	f.f_next = NULL;
	f.f_choice = LDAP_FILTER_AND;
	f.f_and = &nf;
	/* Dummy; we compute scope separately now */
	nf.f_choice = SLAPD_FILTER_COMPUTED;
	nf.f_result = LDAP_SUCCESS;
	nf.f_next = xf.f_or == op->oq_search.rs_filter
		? op->oq_search.rs_filter : &xf ;
	/* Filter depth increased again, adding dummy clause */
	depth++;

#ifdef BDB_SUBENTRIES
	if( get_subentries_visibility( op ) ) {
		struct berval bv_subentry = { sizeof("SUBENTRY")-1, "SUBENTRY" };
		sf.f_choice = LDAP_FILTER_EQUALITY;
		sf.f_ava = &aa_subentry;
		sf.f_av_desc = slap_schema.si_ad_objectClass;
		sf.f_av_value = bv_subentry;
		sf.f_next = nf.f_next;
		nf.f_next = &sf;
	}
#endif

	/* Allocate IDL stack, plus 1 more for former tmp */
	if ( depth+1 > bdb->bi_search_stack_depth ) {
		stack = ch_malloc( (depth + 1) * BDB_IDL_UM_SIZE * sizeof( ID ) );
	} else {
		stack = search_stack( stackop );
	}

	if( op->ors_deref & LDAP_DEREF_SEARCHING ) {
		rc = search_aliases( op, rs, e, locker, ids, scopes, stack );
	} else {
		rc = bdb_dn2idl( op, e, ids, stack );
	}

	if ( rc == LDAP_SUCCESS ) {
		rc = bdb_filter_candidates( op, &f, ids,
			stack, stack+BDB_IDL_UM_SIZE );
	}

	if ( depth+1 > bdb->bi_search_stack_depth ) {
		ch_free( stack );
	}

	if( rc ) {
#ifdef NEW_LOGGING
		LDAP_LOG ( OPERATION, DETAIL1,
			"bdb_search_candidates: failed (rc=%d)\n", rc, 0, 0  );
#else
		Debug(LDAP_DEBUG_TRACE,
			"bdb_search_candidates: failed (rc=%d)\n",
			rc, NULL, NULL );
#endif

	} else {
#ifdef NEW_LOGGING
		LDAP_LOG ( OPERATION, DETAIL1,
			"bdb_search_candidates: id=%ld first=%ld last=%ld\n",
			(long) ids[0], (long) BDB_IDL_FIRST(ids), 
			(long) BDB_IDL_LAST(ids));
#else
		Debug(LDAP_DEBUG_TRACE,
			"bdb_search_candidates: id=%ld first=%ld last=%ld\n",
			(long) ids[0],
			(long) BDB_IDL_FIRST(ids),
			(long) BDB_IDL_LAST(ids) );
#endif
	}

	return rc;
}

#ifdef LDAP_CONTROL_PAGEDRESULTS
static void
send_pagerequest_response( 
	Operation	*op,
	SlapReply	*rs,
	ID		lastid,
	int		tentries )
{
	LDAPControl	ctrl, *ctrls[2];
	char berbuf[LBER_ELEMENT_SIZEOF];
	BerElement	*ber = (BerElement *)berbuf;
	struct berval	cookie = { 0, NULL };
	PagedResultsCookie respcookie;

#ifdef NEW_LOGGING
	LDAP_LOG ( OPERATION, ENTRY,
		"send_pagerequest_response: lastid: (0x%08lx) "
		"nentries: (0x%081x)\n", 
		lastid, rs->sr_nentries, NULL );
#else
	Debug(LDAP_DEBUG_ARGS, "send_pagerequest_response: lastid: (0x%08lx) "
			"nentries: (0x%081x)\n", lastid, rs->sr_nentries, NULL );
#endif

	ctrl.ldctl_value.bv_val = NULL;
	ctrls[0] = &ctrl;
	ctrls[1] = NULL;

	ber_init2( ber, NULL, LBER_USE_DER );

	respcookie = ( PagedResultsCookie )lastid;
	op->o_conn->c_pagedresults_state.ps_cookie = respcookie;
	cookie.bv_len = sizeof( respcookie );
	cookie.bv_val = (char *)&respcookie;

	/*
	 * FIXME: we should consider sending an estimate of the entries
	 * left, after appropriate security check is done
	 */
	ber_printf( ber, "{iO}", tentries, &cookie ); 

	if ( ber_flatten2( ber, &ctrls[0]->ldctl_value, 0 ) == -1 ) {
		goto done;
	}

	ctrls[0]->ldctl_oid = LDAP_CONTROL_PAGEDRESULTS;
	ctrls[0]->ldctl_iscritical = 0;

	rs->sr_ctrls = ctrls;
	rs->sr_err = LDAP_SUCCESS;
	send_ldap_result( op, rs );

done:
	(void) ber_free_buf( ber );
}			
#endif

int
bdb_build_sync_state_ctrl(
	Operation	*op,
	SlapReply	*rs,
	Entry		*e,
	int			entry_sync_state,
	LDAPControl	**ctrls,
	int			num_ctrls,
	int			send_cookie,
	struct berval	*csn)
{
	Attribute* a;
	int ret;
	int res;
	const char *text = NULL;

	char berbuf[LBER_ELEMENT_SIZEOF];
	BerElement *ber = (BerElement *)berbuf;

	struct berval entryuuid_bv	= { 0, NULL };

	ber_init2( ber, 0, LBER_USE_DER );

	ctrls[num_ctrls] = ch_malloc ( sizeof ( LDAPControl ) );

	for ( a = e->e_attrs; a != NULL; a = a->a_next ) {
		AttributeDescription *desc = a->a_desc;
		if ( desc == slap_schema.si_ad_entryUUID ) {
			ber_dupbv( &entryuuid_bv, &a->a_vals[0] );
		}
	}

	if ( send_cookie && csn ) {
		ber_printf( ber, "{eOON}",
			entry_sync_state, &entryuuid_bv, csn );
	} else {
		ber_printf( ber, "{eON}",
			entry_sync_state, &entryuuid_bv );
	}

	ch_free( entryuuid_bv.bv_val );
	entryuuid_bv.bv_val = NULL;

	ctrls[num_ctrls]->ldctl_oid = LDAP_CONTROL_SYNC_STATE;
	ctrls[num_ctrls]->ldctl_iscritical = op->o_sync;
	ret = ber_flatten2( ber, &ctrls[num_ctrls]->ldctl_value, 1 );

	ber_free_buf( ber );

	if ( ret < 0 ) {
#ifdef NEW_LOGGING
		LDAP_LOG ( OPERATION, RESULTS, 
			"bdb_build_sync_ctrl: ber_flatten2 failed\n",
			0, 0, 0 );
#else
		Debug( LDAP_DEBUG_TRACE,
			"bdb_build_sync_ctrl: ber_flatten2 failed\n",
			0, 0, 0 );
#endif
		send_ldap_error( op, rs, LDAP_OTHER, "internal error" );
		return ret;
	}

	return LDAP_SUCCESS;
}

int
bdb_build_sync_done_ctrl(
	Operation	*op,
	SlapReply	*rs,
	LDAPControl	**ctrls,
	int		num_ctrls,
	int		send_cookie,
	struct berval	*csn )
{
	int ret;
	char berbuf[LBER_ELEMENT_SIZEOF];
	BerElement *ber = (BerElement *)berbuf;

	ber_init2( ber, NULL, LBER_USE_DER );

	ctrls[num_ctrls] = ch_malloc ( sizeof ( LDAPControl ) );

	if ( send_cookie && csn ) {
		ber_printf( ber, "{ON}", csn );
	} else {
		ber_printf( ber, "{N}" );
	}

	ctrls[num_ctrls]->ldctl_oid = LDAP_CONTROL_SYNC_DONE;
	ctrls[num_ctrls]->ldctl_iscritical = op->o_sync;
	ret = ber_flatten2( ber, &ctrls[num_ctrls]->ldctl_value, 1 );

	ber_free_buf( ber );

	if ( ret < 0 ) {
#ifdef NEW_LOGGING
		LDAP_LOG ( OPERATION, RESULTS, 
			"bdb_build_sync_done_ctrl: ber_flatten2 failed\n",
			0, 0, 0 );
#else
		Debug( LDAP_DEBUG_TRACE,
			"bdb_build_sync_done_ctrl: ber_flatten2 failed\n",
			0, 0, 0 );
#endif
		send_ldap_error( op, rs, LDAP_OTHER, "internal error" );
		return ret;
	}

	return LDAP_SUCCESS;
}

int
bdb_send_ldap_intermediate(
	Operation   *op,
	SlapReply   *rs,
	int	    state,
	struct berval *cookie )
{
	char berbuf[LBER_ELEMENT_SIZEOF];
	BerElement *ber = (BerElement *)berbuf;
	struct berval rspdata;

	int ret;

	ber_init2( ber, NULL, LBER_USE_DER );

	if ( cookie == NULL ) {
		ber_printf( ber, "{eN}", state );
	} else {
		ber_printf( ber, "{eON}", state, cookie );
	}

	ret = ber_flatten2( ber, &rspdata, 0 );

	if ( ret < 0 ) {
#ifdef NEW_LOGGING
		LDAP_LOG ( OPERATION, RESULTS, 
			"bdb_send_ldap_intermediate: ber_flatten2 failed\n",
			0, 0, 0 );
#else
		Debug( LDAP_DEBUG_TRACE,
			"bdb_send_ldap_intermediate: ber_flatten2 failed\n",
			0, 0, 0 );
#endif
		send_ldap_error( op, rs, LDAP_OTHER, "internal error" );
		return ret;
	}

	rs->sr_rspdata = &rspdata;
	send_ldap_intermediate( op, rs );
	rs->sr_rspdata = NULL;
	ber_free_buf( ber );

	return LDAP_SUCCESS;
}