Exemple #1
0
meta_search_candidate_t
asyncmeta_back_compare_start(Operation *op,
			    SlapReply *rs,
			    a_metaconn_t *mc,
			    bm_context_t *bc,
			    int candidate)
{
	a_dncookie	dc;
	a_metainfo_t	*mi = mc->mc_info;
	a_metatarget_t	*mt = mi->mi_targets[ candidate ];
	struct berval	mdn = BER_BVNULL;
	struct berval	mapped_attr = op->orc_ava->aa_desc->ad_cname;
	struct berval	mapped_value = op->orc_ava->aa_value;
	int rc = 0, nretries = 1;
	LDAPControl	**ctrls = NULL;
	meta_search_candidate_t retcode = META_SEARCH_CANDIDATE;
	BerElement *ber = NULL;
	a_metasingleconn_t	*msc = &mc->mc_conns[ candidate ];
	SlapReply		*candidates = bc->candidates;
	ber_int_t	msgid;

	dc.target = mt;
	dc.conn = op->o_conn;
	dc.rs = rs;
	dc.ctx = "compareDN";

	switch ( asyncmeta_dn_massage( &dc, &op->o_req_dn, &mdn ) ) {
	case LDAP_UNWILLING_TO_PERFORM:
		rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
		retcode = META_SEARCH_ERR;
		goto doreturn;
	default:
		break;
	}

	/*
	 * if attr is objectClass, try to remap the value
	 */
	if ( op->orc_ava->aa_desc == slap_schema.si_ad_objectClass ) {
		asyncmeta_map( &mt->mt_rwmap.rwm_oc,
				&op->orc_ava->aa_value,
				&mapped_value, BACKLDAP_MAP );

		if ( BER_BVISNULL( &mapped_value ) || BER_BVISEMPTY( &mapped_value ) ) {
			rs->sr_err = LDAP_OTHER;
			retcode = META_SEARCH_ERR;
			goto done;
		}

	/*
	 * else try to remap the attribute
	 */
	} else {
		asyncmeta_map( &mt->mt_rwmap.rwm_at,
			&op->orc_ava->aa_desc->ad_cname,
			&mapped_attr, BACKLDAP_MAP );
		if ( BER_BVISNULL( &mapped_attr ) || BER_BVISEMPTY( &mapped_attr ) ) {
			rs->sr_err = LDAP_OTHER;
			retcode = META_SEARCH_ERR;
			goto done;
		}

		if ( op->orc_ava->aa_desc->ad_type->sat_syntax == slap_schema.si_syn_distinguishedName )
		{
			dc.ctx = "compareAttrDN";

			switch ( asyncmeta_dn_massage( &dc, &op->orc_ava->aa_value, &mapped_value ) )
			{
			case LDAP_UNWILLING_TO_PERFORM:
				rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
				retcode = META_SEARCH_ERR;
				goto done;

			default:
				break;
			}
		}
	}
retry:;
	ctrls = op->o_ctrls;
	if ( asyncmeta_controls_add( op, rs, mc, candidate, &ctrls ) != LDAP_SUCCESS )
	{
		candidates[ candidate ].sr_msgid = META_MSGID_IGNORE;
		retcode = META_SEARCH_ERR;
		goto done;
	}

	ber = ldap_build_compare_req( msc->msc_ld, mdn.bv_val, mapped_attr.bv_val, &mapped_value,
			ctrls, NULL, &msgid);
	if (ber) {
		candidates[ candidate ].sr_msgid = msgid;
		rc = ldap_send_initial_request( msc->msc_ld, LDAP_REQ_COMPARE,
						mdn.bv_val, ber, msgid );
		if (rc == msgid)
			rc = LDAP_SUCCESS;
		else
			rc = LDAP_SERVER_DOWN;

		switch ( rc ) {
		case LDAP_SUCCESS:
			retcode = META_SEARCH_CANDIDATE;
			asyncmeta_set_msc_time(msc);
			break;

		case LDAP_SERVER_DOWN:
			ldap_pvt_thread_mutex_lock( &mc->mc_om_mutex);
			asyncmeta_clear_one_msc(NULL, mc, candidate);
			ldap_pvt_thread_mutex_unlock( &mc->mc_om_mutex);
			if ( nretries && asyncmeta_retry( op, rs, &mc, candidate, LDAP_BACK_DONTSEND ) ) {
				nretries = 0;
				/* if the identity changed, there might be need to re-authz */
				(void)mi->mi_ldap_extra->controls_free( op, rs, &ctrls );
				goto retry;
			}

		default:
			candidates[ candidate ].sr_msgid = META_MSGID_IGNORE;
			retcode = META_SEARCH_ERR;
		}
	}
done:
	(void)mi->mi_ldap_extra->controls_free( op, rs, &ctrls );

	if ( mdn.bv_val != op->o_req_dn.bv_val ) {
		free( mdn.bv_val );
	}

	if ( op->orc_ava->aa_value.bv_val != mapped_value.bv_val ) {
		free( mapped_value.bv_val );
	}

doreturn:;
	Debug( LDAP_DEBUG_TRACE, "%s <<< asyncmeta_back_compare_start[%p]=%d\n", op->o_log_prefix, msc, candidates[candidate].sr_msgid );
	return retcode;
}
Exemple #2
0
meta_search_candidate_t
asyncmeta_back_add_start(Operation *op,
			 SlapReply *rs,
			 a_metaconn_t *mc,
			 bm_context_t *bc,
			 int candidate)
{
	int		isupdate;
	Attribute	*a;
	int i;
	LDAPMod		**attrs;
	struct berval	mapped;
	a_dncookie	dc;
	a_metainfo_t	*mi = mc->mc_info;
	a_metatarget_t	*mt = mi->mi_targets[ candidate ];
	struct berval   mdn;
	meta_search_candidate_t retcode = META_SEARCH_CANDIDATE;
	BerElement *ber = NULL;
	a_metasingleconn_t	*msc = &mc->mc_conns[ candidate ];
	SlapReply		*candidates = bc->candidates;
	ber_int_t	msgid;
	LDAPControl		**ctrls = NULL;
	int rc, nretries = 1;


	dc.target = mt;
	dc.conn = op->o_conn;
	dc.rs = rs;
	dc.ctx = "addDN";

	mdn.bv_len = 0;

	switch (asyncmeta_dn_massage( &dc, &bc->op->o_req_dn, &mdn ) )
	{
	case LDAP_SUCCESS:
		break;
	case LDAP_UNWILLING_TO_PERFORM:
		rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
		rs->sr_text = "Operation not allowed";
		retcode = META_SEARCH_ERR;
		goto doreturn;
	default:
		rs->sr_err = LDAP_NO_SUCH_OBJECT;
		retcode = META_SEARCH_NOT_CANDIDATE;
		goto doreturn;
	}

	/* Count number of attributes in entry ( +1 ) */
	for ( i = 1, a = op->ora_e->e_attrs; a; i++, a = a->a_next );

	/* Create array of LDAPMods for ldap_add() */
	attrs = ch_malloc( sizeof( LDAPMod * )*i );

	dc.ctx = "addAttrDN";
	isupdate = be_shadow_update( op );
	for ( i = 0, a = op->ora_e->e_attrs; a; a = a->a_next ) {
		int j, is_oc = 0;

		if ( !isupdate && !get_relax( op ) && a->a_desc->ad_type->sat_no_user_mod  )
		{
			continue;
		}

		if ( a->a_desc == slap_schema.si_ad_objectClass
				|| a->a_desc == slap_schema.si_ad_structuralObjectClass )
		{
			is_oc = 1;
			mapped = a->a_desc->ad_cname;

		} else {
			asyncmeta_map( &mt->mt_rwmap.rwm_at,
					&a->a_desc->ad_cname, &mapped, BACKLDAP_MAP );
			if ( BER_BVISNULL( &mapped ) || BER_BVISEMPTY( &mapped ) ) {
				continue;
			}
		}

		attrs[ i ] = ch_malloc( sizeof( LDAPMod ) );
		if ( attrs[ i ] == NULL ) {
			continue;
		}
		attrs[ i ]->mod_op = LDAP_MOD_BVALUES;
		attrs[ i ]->mod_type = mapped.bv_val;

		if ( is_oc ) {
			for ( j = 0; !BER_BVISNULL( &a->a_vals[ j ] ); j++ );

			attrs[ i ]->mod_bvalues =
				(struct berval **)ch_malloc( ( j + 1 ) *
				sizeof( struct berval * ) );
			for ( j = 0; !BER_BVISNULL( &a->a_vals[ j ] ); ) {
				struct ldapmapping	*mapping;

				asyncmeta_mapping( &mt->mt_rwmap.rwm_oc,
						&a->a_vals[ j ], &mapping, BACKLDAP_MAP );

				if ( mapping == NULL ) {
					if ( mt->mt_rwmap.rwm_oc.drop_missing ) {
						continue;
					}
					attrs[ i ]->mod_bvalues[ j ] = &a->a_vals[ j ];

				} else {
					attrs[ i ]->mod_bvalues[ j ] = &mapping->dst;
				}
				j++;
			}
			attrs[ i ]->mod_bvalues[ j ] = NULL;

		} else {
			/*
			 * FIXME: dn-valued attrs should be rewritten
			 * to allow their use in ACLs at the back-ldap
			 * level.
			 */
			if ( a->a_desc->ad_type->sat_syntax ==
				slap_schema.si_syn_distinguishedName )
			{
				(void)asyncmeta_dnattr_rewrite( &dc, a->a_vals );
				if ( a->a_vals == NULL ) {
					continue;
				}
			}

			for ( j = 0; !BER_BVISNULL( &a->a_vals[ j ] ); j++ )
				;

			attrs[ i ]->mod_bvalues = ch_malloc( ( j + 1 ) * sizeof( struct berval * ) );
			for ( j = 0; !BER_BVISNULL( &a->a_vals[ j ] ); j++ ) {
				attrs[ i ]->mod_bvalues[ j ] = &a->a_vals[ j ];
			}
			attrs[ i ]->mod_bvalues[ j ] = NULL;
		}
		i++;
	}
	attrs[ i ] = NULL;

retry:;
	ctrls = op->o_ctrls;
	if ( asyncmeta_controls_add( op, rs, mc, candidate, &ctrls ) != LDAP_SUCCESS )
	{
		candidates[ candidate ].sr_msgid = META_MSGID_IGNORE;
		retcode = META_SEARCH_ERR;
		goto done;
	}

	ber = ldap_build_add_req( msc->msc_ld, mdn.bv_val, attrs, ctrls, NULL, &msgid);
	if (ber) {
		candidates[ candidate ].sr_msgid = msgid;
		rc = ldap_send_initial_request( msc->msc_ld, LDAP_REQ_ADD,
						mdn.bv_val, ber, msgid );
		if (rc == msgid)
			rc = LDAP_SUCCESS;
		else
			rc = LDAP_SERVER_DOWN;

		switch ( rc ) {
		case LDAP_SUCCESS:
			retcode = META_SEARCH_CANDIDATE;
			asyncmeta_set_msc_time(msc);
			break;

		case LDAP_SERVER_DOWN:
			ldap_pvt_thread_mutex_lock( &mc->mc_om_mutex);
			asyncmeta_clear_one_msc(NULL, mc, candidate);
			ldap_pvt_thread_mutex_unlock( &mc->mc_om_mutex);
			if ( nretries && asyncmeta_retry( op, rs, &mc, candidate, LDAP_BACK_DONTSEND ) ) {
				nretries = 0;
				/* if the identity changed, there might be need to re-authz */
				(void)mi->mi_ldap_extra->controls_free( op, rs, &ctrls );
				goto retry;
			}

		default:
			candidates[ candidate ].sr_msgid = META_MSGID_IGNORE;
			retcode = META_SEARCH_ERR;
		}
	}

done:

	(void)mi->mi_ldap_extra->controls_free( op, rs, &ctrls );

	for ( --i; i >= 0; --i ) {
		free( attrs[ i ]->mod_bvalues );
		free( attrs[ i ] );
	}
	free( attrs );
	if ( mdn.bv_val != op->ora_e->e_dn ) {
		free( mdn.bv_val );
		BER_BVZERO( &mdn );
	}

doreturn:;
	Debug( LDAP_DEBUG_TRACE, "%s <<< asyncmeta_back_add_start[%p]=%d\n", op->o_log_prefix, msc, candidates[candidate].sr_msgid );
	return retcode;
}
Exemple #3
0
meta_search_candidate_t
asyncmeta_back_modrdn_start(Operation *op,
			    SlapReply *rs,
			    a_metaconn_t *mc,
			    bm_context_t *bc,
			    int candidate)
{
	a_dncookie	dc;
	a_metainfo_t	*mi = mc->mc_info;
	a_metatarget_t	*mt = mi->mi_targets[ candidate ];
	struct berval	mdn = BER_BVNULL,
		mnewSuperior = BER_BVNULL,
		newrdn = BER_BVNULL;
	int rc = 0, nretries = 1;
	LDAPControl	**ctrls = NULL;
	meta_search_candidate_t retcode = META_SEARCH_CANDIDATE;
	BerElement *ber = NULL;
	a_metasingleconn_t	*msc = &mc->mc_conns[ candidate ];
	SlapReply		*candidates = bc->candidates;
	ber_int_t	msgid;

	dc.target = mt;
	dc.conn = op->o_conn;
	dc.rs = rs;

	if ( op->orr_newSup ) {

		/*
		 * NOTE: the newParent, if defined, must be on the
		 * same target as the entry to be renamed.  This check
		 * has been anticipated in meta_back_getconn()
		 */
		/*
		 * FIXME: one possibility is to delete the entry
		 * from one target and add it to the other;
		 * unfortunately we'd need write access to both,
		 * which is nearly impossible; for administration
		 * needs, the rootdn of the metadirectory could
		 * be mapped to an administrative account on each
		 * target (the binddn?); we'll see.
		 */
		/*
		 * NOTE: we need to port the identity assertion
		 * feature from back-ldap
		 */

		/* needs LDAPv3 */
		switch ( mt->mt_version ) {
		case LDAP_VERSION3:
			break;

		case 0:
			if ( op->o_protocol == 0 || op->o_protocol == LDAP_VERSION3 ) {
				break;
			}
			/* fall thru */

		default:
			/* op->o_protocol cannot be anything but LDAPv3,
			 * otherwise wouldn't be here */
			rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
			retcode = META_SEARCH_ERR;
			goto done;
		}

		/*
		 * Rewrite the new superior, if defined and required
		 */
		dc.ctx = "newSuperiorDN";
		if ( asyncmeta_dn_massage( &dc, op->orr_newSup, &mnewSuperior ) ) {
			rs->sr_err = LDAP_OTHER;
			retcode = META_SEARCH_ERR;
			goto done;
		}
	}

	/*
	 * Rewrite the modrdn dn, if required
	 */
	dc.ctx = "modrDN";
	if ( asyncmeta_dn_massage( &dc, &op->o_req_dn, &mdn ) ) {
		rs->sr_err = LDAP_OTHER;
		retcode = META_SEARCH_ERR;
		goto done;
	}

	/* NOTE: we need to copy the newRDN in case it was formed
	 * from a DN by simply changing the length (ITS#5397) */
	newrdn = op->orr_newrdn;
	if ( newrdn.bv_val[ newrdn.bv_len ] != '\0' ) {
		ber_dupbv_x( &newrdn, &op->orr_newrdn, op->o_tmpmemctx );
	}
retry:;
	ctrls = op->o_ctrls;
	if ( asyncmeta_controls_add( op, rs, mc, candidate, &ctrls ) != LDAP_SUCCESS )
	{
		candidates[ candidate ].sr_msgid = META_MSGID_IGNORE;
		retcode = META_SEARCH_ERR;
		goto done;
	}

	ber = ldap_build_moddn_req( msc->msc_ld, mdn.bv_val, newrdn.bv_val,
			mnewSuperior.bv_val, op->orr_deleteoldrdn, ctrls, NULL, &msgid);
	if (ber) {
		candidates[ candidate ].sr_msgid = msgid;
		rc = ldap_send_initial_request( msc->msc_ld, LDAP_REQ_MODRDN,
						mdn.bv_val, ber, msgid );
		if (rc == msgid)
			rc = LDAP_SUCCESS;
		else
			rc = LDAP_SERVER_DOWN;

		switch ( rc ) {
		case LDAP_SUCCESS:
			retcode = META_SEARCH_CANDIDATE;
			asyncmeta_set_msc_time(msc);
			break;

		case LDAP_SERVER_DOWN:
			ldap_pvt_thread_mutex_lock( &mc->mc_om_mutex);
			asyncmeta_clear_one_msc(NULL, mc, candidate);
			ldap_pvt_thread_mutex_unlock( &mc->mc_om_mutex);
			if ( nretries && asyncmeta_retry( op, rs, &mc, candidate, LDAP_BACK_DONTSEND ) ) {
				nretries = 0;
				/* if the identity changed, there might be need to re-authz */
				(void)mi->mi_ldap_extra->controls_free( op, rs, &ctrls );
				goto retry;
			}

		default:
			candidates[ candidate ].sr_msgid = META_MSGID_IGNORE;
			retcode = META_SEARCH_ERR;
		}
	}

done:
	(void)mi->mi_ldap_extra->controls_free( op, rs, &ctrls );

	if ( mdn.bv_val != op->o_req_dn.bv_val ) {
		free( mdn.bv_val );
		BER_BVZERO( &mdn );
	}

	if ( !BER_BVISNULL( &mnewSuperior )
			&& mnewSuperior.bv_val != op->orr_newSup->bv_val )
	{
		free( mnewSuperior.bv_val );
		BER_BVZERO( &mnewSuperior );
	}

	if ( newrdn.bv_val != op->orr_newrdn.bv_val ) {
		op->o_tmpfree( newrdn.bv_val, op->o_tmpmemctx );
	}

doreturn:;
	Debug( LDAP_DEBUG_TRACE, "%s <<< asyncmeta_back_modrdn_start[%p]=%d\n", op->o_log_prefix, msc, candidates[candidate].sr_msgid );
	return retcode;
}
Exemple #4
0
/*
 * asyncmeta_single_bind
 *
 * attempts to perform a bind with creds
 */
static int
asyncmeta_single_bind(
	Operation		*op,
	SlapReply		*rs,
	a_metaconn_t		*mc,
	int			candidate )
{
	a_metainfo_t		*mi = mc->mc_info;
	a_metatarget_t		*mt = mi->mi_targets[ candidate ];
	struct berval		mdn = BER_BVNULL;
	a_metasingleconn_t	*msc = &mc->mc_conns[ candidate ];
	int			msgid;
	a_dncookie		dc;
	struct berval		save_o_dn;
	int			save_o_do_not_cache;
	LDAPControl		**ctrls = NULL;

	if ( !BER_BVISNULL( &msc->msc_bound_ndn ) ) {
		ch_free( msc->msc_bound_ndn.bv_val );
		BER_BVZERO( &msc->msc_bound_ndn );
	}

	if ( !BER_BVISNULL( &msc->msc_cred ) ) {
		/* destroy sensitive data */
		memset( msc->msc_cred.bv_val, 0, msc->msc_cred.bv_len );
		ch_free( msc->msc_cred.bv_val );
		BER_BVZERO( &msc->msc_cred );
	}

	/*
	 * Rewrite the bind dn if needed
	 */
	dc.target = mt;
	dc.conn = op->o_conn;
	dc.rs = rs;
	dc.ctx = "bindDN";

	if ( asyncmeta_dn_massage( &dc, &op->o_req_dn, &mdn ) ) {
		rs->sr_text = "DN rewrite error";
		rs->sr_err = LDAP_OTHER;
		return rs->sr_err;
	}

	/* don't add proxyAuthz; set the bindDN */
	save_o_dn = op->o_dn;
	save_o_do_not_cache = op->o_do_not_cache;
	op->o_do_not_cache = 1;
	op->o_dn = op->o_req_dn;

	ctrls = op->o_ctrls;
	rs->sr_err = asyncmeta_controls_add( op, rs, mc, candidate, &ctrls );
	op->o_dn = save_o_dn;
	op->o_do_not_cache = save_o_do_not_cache;
	if ( rs->sr_err != LDAP_SUCCESS ) {
		goto return_results;
	}

	/* FIXME: this fixes the bind problem right now; we need
	 * to use the asynchronous version to get the "matched"
	 * and more in case of failure ... */
	/* FIXME: should we check if at least some of the op->o_ctrls
	 * can/should be passed? */
	for (;;) {
		rs->sr_err = ldap_sasl_bind( msc->msc_ld, mdn.bv_val,
			LDAP_SASL_SIMPLE, &op->orb_cred,
			ctrls, NULL, &msgid );
		if ( rs->sr_err != LDAP_X_CONNECTING ) {
			break;
		}
		ldap_pvt_thread_yield();
	}

	mi->mi_ldap_extra->controls_free( op, rs, &ctrls );

	asyncmeta_bind_op_result( op, rs, mc, candidate, msgid, LDAP_BACK_DONTSEND, 1 );
	if ( rs->sr_err != LDAP_SUCCESS ) {
		goto return_results;
	}

	/* If defined, proxyAuthz will be used also when
	 * back-ldap is the authorizing backend; for this
	 * purpose, a successful bind is followed by a
	 * bind with the configured identity assertion */
	/* NOTE: use with care */
	if ( mt->mt_idassert_flags & LDAP_BACK_AUTH_OVERRIDE ) {
		asyncmeta_proxy_authz_bind( mc, candidate, op, rs, LDAP_BACK_SENDERR, 1 );
		if ( !LDAP_BACK_CONN_ISBOUND( msc ) ) {
			goto return_results;
		}
		goto cache_refresh;
	}

	ber_bvreplace( &msc->msc_bound_ndn, &op->o_req_ndn );
	LDAP_BACK_CONN_ISBOUND_SET( msc );
	mc->mc_authz_target = candidate;

	if ( META_BACK_TGT_SAVECRED( mt ) ) {
		if ( !BER_BVISNULL( &msc->msc_cred ) ) {
			memset( msc->msc_cred.bv_val, 0,
				msc->msc_cred.bv_len );
		}
		ber_bvreplace( &msc->msc_cred, &op->orb_cred );
		ldap_set_rebind_proc( msc->msc_ld, mt->mt_rebind_f, msc );
	}

cache_refresh:;
	if ( mi->mi_cache.ttl != META_DNCACHE_DISABLED
			&& !BER_BVISEMPTY( &op->o_req_ndn ) )
	{
		( void )asyncmeta_dncache_update_entry( &mi->mi_cache,
				&op->o_req_ndn, candidate );
	}

return_results:;
	if ( mdn.bv_val != op->o_req_dn.bv_val ) {
		free( mdn.bv_val );
	}

	if ( META_BACK_TGT_QUARANTINE( mt ) ) {
		asyncmeta_quarantine( op, mi, rs, candidate );
	}
	ldap_unbind_ext( msc->msc_ld, NULL, NULL );
	msc->msc_ld = NULL;
	ldap_ld_free( msc->msc_ldr, 0, NULL, NULL );
	msc->msc_ldr = NULL;
	return rs->sr_err;
}
Exemple #5
0
meta_search_candidate_t
asyncmeta_back_search_start(
				Operation *op,
				SlapReply *rs,
			    a_metaconn_t *mc,
			    bm_context_t *bc,
			    int candidate,
			    struct berval		*prcookie,
			    ber_int_t		prsize )
{
	SlapReply		*candidates = bc->candidates;
	a_metainfo_t		*mi = ( a_metainfo_t * )mc->mc_info;
	a_metatarget_t		*mt = mi->mi_targets[ candidate ];
	a_metasingleconn_t	*msc = &mc->mc_conns[ candidate ];
	a_dncookie		dc;
	struct berval		realbase = op->o_req_dn;
	int			realscope = op->ors_scope;
	struct berval		mbase = BER_BVNULL;
	struct berval		mfilter = BER_BVNULL;
	char			**mapped_attrs = NULL;
	int			rc;
	meta_search_candidate_t	retcode;
	int timelimit;
	int			nretries = 1;
	LDAPControl		**ctrls = NULL;
	BerElement *ber;
	ber_int_t	msgid;
#ifdef SLAPD_META_CLIENT_PR
	LDAPControl		**save_ctrls = NULL;
#endif /* SLAPD_META_CLIENT_PR */

	/* this should not happen; just in case... */
	if ( msc->msc_ld == NULL ) {
		Debug( LDAP_DEBUG_ANY,
			"%s: asyncmeta_back_search_start candidate=%d ld=NULL%s.\n",
			op->o_log_prefix, candidate,
			META_BACK_ONERR_STOP( mi ) ? "" : " (ignored)" );
		candidates[ candidate ].sr_err = LDAP_OTHER;
		if ( META_BACK_ONERR_STOP( mi ) ) {
			return META_SEARCH_ERR;
		}
		candidates[ candidate ].sr_msgid = META_MSGID_IGNORE;
		return META_SEARCH_NOT_CANDIDATE;
	}

	Debug( LDAP_DEBUG_TRACE, "%s >>> asyncmeta_back_search_start[%d]\n", op->o_log_prefix, candidate, 0 );
	/*
	 * modifies the base according to the scope, if required
	 */
	if ( mt->mt_nsuffix.bv_len > op->o_req_ndn.bv_len ) {
		switch ( op->ors_scope ) {
		case LDAP_SCOPE_SUBTREE:
			/*
			 * make the target suffix the new base
			 * FIXME: this is very forgiving, because
			 * "illegal" searchBases may be turned
			 * into the suffix of the target; however,
			 * the requested searchBase already passed
			 * thru the candidate analyzer...
			 */
			if ( dnIsSuffix( &mt->mt_nsuffix, &op->o_req_ndn ) ) {
				realbase = mt->mt_nsuffix;
				if ( mt->mt_scope == LDAP_SCOPE_SUBORDINATE ) {
					realscope = LDAP_SCOPE_SUBORDINATE;
				}

			} else {
				/*
				 * this target is no longer candidate
				 */
				retcode = META_SEARCH_NOT_CANDIDATE;
				goto doreturn;
			}
			break;

		case LDAP_SCOPE_SUBORDINATE:
		case LDAP_SCOPE_ONELEVEL:
		{
			struct berval	rdn = mt->mt_nsuffix;
			rdn.bv_len -= op->o_req_ndn.bv_len + STRLENOF( "," );
			if ( dnIsOneLevelRDN( &rdn )
					&& dnIsSuffix( &mt->mt_nsuffix, &op->o_req_ndn ) )
			{
				/*
				 * if there is exactly one level,
				 * make the target suffix the new
				 * base, and make scope "base"
				 */
				realbase = mt->mt_nsuffix;
				if ( op->ors_scope == LDAP_SCOPE_SUBORDINATE ) {
					if ( mt->mt_scope == LDAP_SCOPE_SUBORDINATE ) {
						realscope = LDAP_SCOPE_SUBORDINATE;
					} else {
						realscope = LDAP_SCOPE_SUBTREE;
					}
				} else {
					realscope = LDAP_SCOPE_BASE;
				}
				break;
			} /* else continue with the next case */
		}

		case LDAP_SCOPE_BASE:
			/*
			 * this target is no longer candidate
			 */
			retcode = META_SEARCH_NOT_CANDIDATE;
			goto doreturn;
		}
	}

	/* check filter expression */
	if ( mt->mt_filter ) {
		metafilter_t *mf;
		for ( mf = mt->mt_filter; mf; mf = mf->mf_next ) {
			if ( regexec( &mf->mf_regex, op->ors_filterstr.bv_val, 0, NULL, 0 ) == 0 )
				break;
		}
		/* nothing matched, this target is no longer a candidate */
		if ( !mf ) {
			retcode = META_SEARCH_NOT_CANDIDATE;
			goto doreturn;
		}
	}

	/*
	 * Rewrite the search base, if required
	 */
	dc.target = mt;
	dc.ctx = "searchBase";
	dc.conn = op->o_conn;
	dc.rs = rs;
	switch ( asyncmeta_dn_massage( &dc, &realbase, &mbase ) ) {
	case LDAP_SUCCESS:
		break;

	case LDAP_UNWILLING_TO_PERFORM:
		rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
		rs->sr_text = "Operation not allowed";
		retcode = META_SEARCH_ERR;
		goto doreturn;

	default:

		/*
		 * this target is no longer candidate
		 */
		retcode = META_SEARCH_NOT_CANDIDATE;
		goto doreturn;
	}

	/*
	 * Maps filter
	 */
	rc = asyncmeta_filter_map_rewrite( &dc, op->ors_filter,
			&mfilter, BACKLDAP_MAP, NULL );
	switch ( rc ) {
	case LDAP_SUCCESS:
		break;

	case LDAP_COMPARE_FALSE:
	default:
		/*
		 * this target is no longer candidate
		 */
		retcode = META_SEARCH_NOT_CANDIDATE;
		goto done;
	}

	/*
	 * Maps required attributes
	 */
	rc = asyncmeta_map_attrs( op, &mt->mt_rwmap.rwm_at,
			op->ors_attrs, BACKLDAP_MAP, &mapped_attrs );
	if ( rc != LDAP_SUCCESS ) {
		/*
		 * this target is no longer candidate
		 */
		retcode = META_SEARCH_NOT_CANDIDATE;
		goto done;
	}

	if ( op->ors_tlimit != SLAP_NO_LIMIT ) {
		timelimit = op->ors_tlimit > 0 ? op->ors_tlimit : 1;
	} else {
		timelimit = -1;	/* no limit */
	}

#ifdef SLAPD_META_CLIENT_PR
	save_ctrls = op->o_ctrls;
	{
		LDAPControl *pr_c = NULL;
		int i = 0, nc = 0;

		if ( save_ctrls ) {
			for ( ; save_ctrls[i] != NULL; i++ );
			nc = i;
			pr_c = ldap_control_find( LDAP_CONTROL_PAGEDRESULTS, save_ctrls, NULL );
		}

		if ( pr_c != NULL ) nc--;
		if ( mt->mt_ps > 0 || prcookie != NULL ) nc++;

		if ( mt->mt_ps > 0 || prcookie != NULL || pr_c != NULL ) {
			int src = 0, dst = 0;
			BerElementBuffer berbuf;
			BerElement *ber = (BerElement *)&berbuf;
			struct berval val = BER_BVNULL;
			ber_len_t len;

			len = sizeof( LDAPControl * )*( nc + 1 ) + sizeof( LDAPControl );

			if ( mt->mt_ps > 0 || prcookie != NULL ) {
				struct berval nullcookie = BER_BVNULL;
				ber_tag_t tag;

				if ( prsize == 0 && mt->mt_ps > 0 ) prsize = mt->mt_ps;
				if ( prcookie == NULL ) prcookie = &nullcookie;

				ber_init2( ber, NULL, LBER_USE_DER );
				tag = ber_printf( ber, "{iO}", prsize, prcookie );
				if ( tag == LBER_ERROR ) {
					/* error */
					(void) ber_free_buf( ber );
					goto done_pr;
				}

				tag = ber_flatten2( ber, &val, 0 );
				if ( tag == LBER_ERROR ) {
					/* error */
					(void) ber_free_buf( ber );
					goto done_pr;
				}

				len += val.bv_len + 1;
			}

			op->o_ctrls = op->o_tmpalloc( len, op->o_tmpmemctx );
			if ( save_ctrls ) {
				for ( ; save_ctrls[ src ] != NULL; src++ ) {
					if ( save_ctrls[ src ] != pr_c ) {
						op->o_ctrls[ dst ] = save_ctrls[ src ];
						dst++;
					}
				}
			}

			if ( mt->mt_ps > 0 || prcookie != NULL ) {
				op->o_ctrls[ dst ] = (LDAPControl *)&op->o_ctrls[ nc + 1 ];

				op->o_ctrls[ dst ]->ldctl_oid = LDAP_CONTROL_PAGEDRESULTS;
				op->o_ctrls[ dst ]->ldctl_iscritical = 1;

				op->o_ctrls[ dst ]->ldctl_value.bv_val = (char *)&op->o_ctrls[ dst ][ 1 ];
				AC_MEMCPY( op->o_ctrls[ dst ]->ldctl_value.bv_val, val.bv_val, val.bv_len + 1 );
				op->o_ctrls[ dst ]->ldctl_value.bv_len = val.bv_len;
				dst++;

				(void)ber_free_buf( ber );
			}

			op->o_ctrls[ dst ] = NULL;
		}
done_pr:;
	}
#endif /* SLAPD_META_CLIENT_PR */

retry:;
	asyncmeta_set_msc_time(msc);
	ctrls = op->o_ctrls;
	if (nretries == 0)
	{
		if (rc != LDAP_SUCCESS)
		{
			rs->sr_err = LDAP_BUSY;
			retcode = META_SEARCH_ERR;
			candidates[ candidate ].sr_msgid = META_MSGID_IGNORE;
		        goto done;
		}
	}

	if ( asyncmeta_controls_add( op, rs, mc, candidate, &ctrls )
		!= LDAP_SUCCESS )
	{
		candidates[ candidate ].sr_msgid = META_MSGID_IGNORE;
		retcode = META_SEARCH_NOT_CANDIDATE;
		goto done;
	}

	/*
	 * Starts the search
	 */
	ber = ldap_build_search_req( msc->msc_ld,
			mbase.bv_val, realscope, mfilter.bv_val,
			mapped_attrs, op->ors_attrsonly,
			ctrls, NULL, timelimit, op->ors_slimit, op->ors_deref,
			&msgid );
	if (ber) {
		candidates[ candidate ].sr_msgid = msgid;
		rc = ldap_send_initial_request( msc->msc_ld, LDAP_REQ_SEARCH,
			mbase.bv_val, ber, msgid );
		if (rc == msgid)
			rc = LDAP_SUCCESS;
		else
			rc = LDAP_SERVER_DOWN;
		switch ( rc ) {
		case LDAP_SUCCESS:
			retcode = META_SEARCH_CANDIDATE;
			asyncmeta_set_msc_time(msc);
			break;

		case LDAP_SERVER_DOWN:
			ldap_pvt_thread_mutex_lock( &mc->mc_om_mutex);
			if (mc->mc_active < 1) {
				asyncmeta_clear_one_msc(NULL, mc, candidate);
			}
			ldap_pvt_thread_mutex_unlock( &mc->mc_om_mutex);
			if ( nretries && asyncmeta_retry( op, rs, &mc, candidate, LDAP_BACK_DONTSEND ) ) {
				nretries = 0;
				/* if the identity changed, there might be need to re-authz */
				(void)mi->mi_ldap_extra->controls_free( op, rs, &ctrls );
				goto retry;
			}
			rs->sr_err = LDAP_UNAVAILABLE;
			retcode = META_SEARCH_ERR;
			break;
		default:
			candidates[ candidate ].sr_msgid = META_MSGID_IGNORE;
			retcode = META_SEARCH_NOT_CANDIDATE;
		}
	}

done:;
	(void)mi->mi_ldap_extra->controls_free( op, rs, &ctrls );
#ifdef SLAPD_META_CLIENT_PR
	if ( save_ctrls != op->o_ctrls ) {
		op->o_tmpfree( op->o_ctrls, op->o_tmpmemctx );
		op->o_ctrls = save_ctrls;
	}
#endif /* SLAPD_META_CLIENT_PR */

	if ( mapped_attrs ) {
		ber_memfree_x( mapped_attrs, op->o_tmpmemctx );
	}
	if ( mfilter.bv_val != op->ors_filterstr.bv_val ) {
		ber_memfree_x( mfilter.bv_val, NULL );
	}
	if ( mbase.bv_val != realbase.bv_val ) {
		free( mbase.bv_val );
	}

doreturn:;
	Debug( LDAP_DEBUG_TRACE, "%s <<< asyncmeta_back_search_start[%p]=%d\n", op->o_log_prefix, msc, candidates[candidate].sr_msgid );
	return retcode;
}