Adding upstream version 2.5.13+dfsg.upstream/2.5.13+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1893 insertions, 0 deletions

diff --git a/servers/slapd/back-meta/conn.c b/servers/slapd/back-meta/conn.c
new file mode 100644
index 0000000..91fdad3
--- /dev/null
+++ b/servers/slapd/back-meta/conn.c
@@ -0,0 +1,1893 @@
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 1999-2022 The OpenLDAP Foundation.
+ * Portions Copyright 2001-2003 Pierangelo Masarati.
+ * Portions Copyright 1999-2003 Howard Chu.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+/* ACKNOWLEDGEMENTS:
+ * This work was initially developed by the Howard Chu for inclusion
+ * in OpenLDAP Software and subsequently enhanced by Pierangelo
+ * Masarati.
+ */
+
+#include "portable.h"
+
+#include <stdio.h>
+
+#include <ac/errno.h>
+#include <ac/socket.h>
+#include <ac/string.h>
+
+
+#define AVL_INTERNAL
+#include "slap.h"
+#include "../back-ldap/back-ldap.h"
+#include "back-meta.h"
+
+/*
+ * meta_back_conndn_cmp
+ *
+ * compares two struct metaconn based on the value of the conn pointer
+ * and of the local DN; used by avl stuff
+ */
+int
+meta_back_conndn_cmp(
+	const void *c1,
+	const void *c2 )
+{
+	metaconn_t	*mc1 = ( metaconn_t * )c1;
+        metaconn_t	*mc2 = ( metaconn_t * )c2;
+	int		rc;
+	
+	/* If local DNs don't match, it is definitely not a match */
+	/* For shared sessions, conn is NULL. Only explicitly
+	 * bound sessions will have non-NULL conn.
+	 */
+	rc = SLAP_PTRCMP( mc1->mc_conn, mc2->mc_conn );
+	if ( rc == 0 ) {
+		rc = ber_bvcmp( &mc1->mc_local_ndn, &mc2->mc_local_ndn );
+	}
+
+	return rc;
+}
+
+/*
+ * meta_back_conndnmc_cmp
+ *
+ * compares two struct metaconn based on the value of the conn pointer,
+ * the local DN and the struct pointer; used by avl stuff
+ */
+static int
+meta_back_conndnmc_cmp(
+	const void *c1,
+	const void *c2 )
+{
+	metaconn_t	*mc1 = ( metaconn_t * )c1;
+        metaconn_t	*mc2 = ( metaconn_t * )c2;
+	int		rc;
+	
+	/* If local DNs don't match, it is definitely not a match */
+	/* For shared sessions, conn is NULL. Only explicitly
+	 * bound sessions will have non-NULL conn.
+	 */
+	rc = SLAP_PTRCMP( mc1->mc_conn, mc2->mc_conn );
+	if ( rc == 0 ) {
+		rc = ber_bvcmp( &mc1->mc_local_ndn, &mc2->mc_local_ndn );
+		if ( rc == 0 ) {
+			rc = SLAP_PTRCMP( mc1, mc2 );
+		}
+	}
+
+	return rc;
+}
+
+/*
+ * meta_back_conn_cmp
+ *
+ * compares two struct metaconn based on the value of the conn pointer;
+ * used by avl stuff
+ */
+int
+meta_back_conn_cmp(
+	const void *c1,
+	const void *c2 )
+{
+	metaconn_t	*mc1 = ( metaconn_t * )c1;
+        metaconn_t	*mc2 = ( metaconn_t * )c2;
+	
+	/* For shared sessions, conn is NULL. Only explicitly
+	 * bound sessions will have non-NULL conn.
+	 */
+	return SLAP_PTRCMP( mc1->mc_conn, mc2->mc_conn );
+}
+
+/*
+ * meta_back_conndn_dup
+ *
+ * returns -1 in case a duplicate struct metaconn has been inserted;
+ * used by avl stuff
+ */
+int
+meta_back_conndn_dup(
+	void *c1,
+	void *c2 )
+{
+	metaconn_t	*mc1 = ( metaconn_t * )c1;
+	metaconn_t	*mc2 = ( metaconn_t * )c2;
+
+	/* Cannot have more than one shared session with same DN */
+	if ( mc1->mc_conn == mc2->mc_conn &&
+		dn_match( &mc1->mc_local_ndn, &mc2->mc_local_ndn ) )
+	{
+		return -1;
+	}
+		
+	return 0;
+}
+
+/*
+ * Debug stuff (got it from libavl)
+ */
+#if META_BACK_PRINT_CONNTREE > 0
+static void
+meta_back_print( metaconn_t *mc, char *avlstr )
+{
+	int	i;
+
+	fputs( "targets=[", stderr );
+	for ( i = 0; i < mc->mc_info->mi_ntargets; i++ ) {
+		fputc( mc->mc_conns[ i ].msc_ld ? '*' : 'o', stderr);
+	}
+	fputc( ']', stderr );
+
+	fprintf( stderr, " mc=%p local=\"%s\" conn=%p refcnt=%d%s %s\n",
+		(void *)mc,
+		mc->mc_local_ndn.bv_val ? mc->mc_local_ndn.bv_val : "",
+		(void *)mc->mc_conn,
+		mc->mc_refcnt,
+		LDAP_BACK_CONN_TAINTED( mc ) ? " tainted" : "",
+		avlstr );
+}
+
+static void
+meta_back_ravl_print( TAvlnode *root, int depth )
+{
+	int     	i;
+
+	if ( root == 0 ) {
+		return;
+	}
+	
+	meta_back_ravl_print( root->avl_right, depth + 1 );
+	
+	for ( i = 0; i < depth; i++ ) {
+		fprintf( stderr, "-" );
+	}
+	fputc( ' ', stderr );
+
+	meta_back_print( (metaconn_t *)root->avl_data,
+		avl_bf2str( root->avl_bf ) );
+
+	meta_back_ravl_print( root->avl_left, depth + 1 );
+}
+
+/* NOTE: duplicate from back-ldap/bind.c */
+static char* priv2str[] = {
+	"privileged",
+	"privileged/TLS",
+	"anonymous",
+	"anonymous/TLS",
+	"bind",
+	"bind/TLS",
+	NULL
+};
+
+void
+meta_back_print_conntree( metainfo_t *mi, char *msg )
+{
+	int	c;
+
+	fprintf( stderr, "========> %s\n", msg );
+	
+	for ( c = LDAP_BACK_PCONN_FIRST; c < LDAP_BACK_PCONN_LAST; c++ ) {
+		int		i = 0;
+		metaconn_t	*mc;
+
+		fprintf( stderr, "  %s[%d]\n", priv2str[ c ], mi->mi_conn_priv[ c ].mic_num );
+
+		LDAP_TAILQ_FOREACH( mc, &mi->mi_conn_priv[ c ].mic_priv, mc_q )
+		{
+			fprintf( stderr, "    [%d] ", i );
+			meta_back_print( mc, "" );
+			i++;
+		}
+	}
+	
+	if ( mi->mi_conninfo.lai_tree == NULL ) {
+		fprintf( stderr, "\t(empty)\n" );
+
+	} else {
+		meta_back_ravl_print( mi->mi_conninfo.lai_tree, 0 );
+	}
+	
+	fprintf( stderr, "<======== %s\n", msg );
+}
+#endif /* META_BACK_PRINT_CONNTREE */
+/*
+ * End of debug stuff
+ */
+
+/*
+ * metaconn_alloc
+ * 
+ * Allocates a connection structure, making room for all the referenced targets
+ */
+static metaconn_t *
+metaconn_alloc(
+       	Operation 		*op )
+{
+	metainfo_t	*mi = ( metainfo_t * )op->o_bd->be_private;
+	metaconn_t	*mc;
+	int		ntargets = mi->mi_ntargets;
+
+	assert( ntargets > 0 );
+
+	/* malloc all in one */
+	mc = ( metaconn_t * )ch_calloc( 1, sizeof( metaconn_t )
+		+ sizeof( metasingleconn_t ) * ( ntargets - 1 ) );
+	if ( mc == NULL ) {
+		return NULL;
+	}
+
+	mc->mc_info = mi;
+
+	mc->mc_authz_target = META_BOUND_NONE;
+	mc->mc_refcnt = 1;
+
+	return mc;
+}
+
+/*
+ * meta_back_init_one_conn
+ * 
+ * Initializes one connection
+ */
+int
+meta_back_init_one_conn(
+	Operation		*op,
+	SlapReply		*rs,
+	metaconn_t		*mc,
+	int			candidate,
+	int			ispriv,
+	ldap_back_send_t	sendok,
+	int			dolock )
+{
+	metainfo_t		*mi = ( metainfo_t * )op->o_bd->be_private;
+	metatarget_t		*mt = mi->mi_targets[ candidate ];
+	metasingleconn_t	*msc = &mc->mc_conns[ candidate ];
+	int			version;
+	dncookie		dc;
+	int			isauthz = ( candidate == mc->mc_authz_target );
+	int			do_return = 0;
+#ifdef HAVE_TLS
+	int			is_ldaps = 0;
+	int			do_start_tls = 0;
+#endif /* HAVE_TLS */
+
+	/* if the server is quarantined, and
+	 * - the current interval did not expire yet, or
+	 * - no more retries should occur,
+	 * don't return the connection */
+	if ( mt->mt_isquarantined ) {
+		slap_retry_info_t	*ri = &mt->mt_quarantine;
+		int			dont_retry = 0;
+
+		if ( mt->mt_quarantine.ri_interval ) {
+			ldap_pvt_thread_mutex_lock( &mt->mt_quarantine_mutex );
+			dont_retry = ( mt->mt_isquarantined > LDAP_BACK_FQ_NO );
+			if ( dont_retry ) {
+				dont_retry = ( ri->ri_num[ ri->ri_idx ] == SLAP_RETRYNUM_TAIL
+					|| slap_get_time() < ri->ri_last + ri->ri_interval[ ri->ri_idx ] );
+				if ( !dont_retry ) {
+					Debug(LDAP_DEBUG_ANY,
+					      "%s meta_back_init_one_conn[%d]: quarantine " "retry block #%d try #%d.\n",
+					      op->o_log_prefix,
+					      candidate, ri->ri_idx,
+					      ri->ri_count );
+
+					mt->mt_isquarantined = LDAP_BACK_FQ_RETRYING;
+				}
+
+			}
+			ldap_pvt_thread_mutex_unlock( &mt->mt_quarantine_mutex );
+		}
+
+		if ( dont_retry ) {
+			rs->sr_err = LDAP_UNAVAILABLE;
+			if ( op->o_conn && ( sendok & LDAP_BACK_SENDERR ) ) {
+				rs->sr_text = "Target is quarantined";
+				send_ldap_result( op, rs );
+			}
+			return rs->sr_err;
+		}
+	}
+
+retry_lock:;
+	if ( dolock ) {
+		ldap_pvt_thread_mutex_lock( &mi->mi_conninfo.lai_mutex );
+	}
+
+	/*
+	 * Already init'ed
+	 */
+	if ( LDAP_BACK_CONN_ISBOUND( msc )
+		|| LDAP_BACK_CONN_ISANON( msc ) )
+	{
+		assert( msc->msc_ld != NULL );
+		rs->sr_err = LDAP_SUCCESS;
+		do_return = 1;
+
+	} else if ( META_BACK_CONN_CREATING( msc )
+		|| LDAP_BACK_CONN_BINDING( msc ) )
+	{
+		if ( !LDAP_BACK_USE_TEMPORARIES( mi ) ) {
+			if ( dolock ) {
+				ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
+			}
+
+			ldap_pvt_thread_yield();
+			goto retry_lock;
+		}
+
+		/* sounds more appropriate */
+		rs->sr_err = LDAP_BUSY;
+		rs->sr_text = "No connections to target are available";
+		do_return = 1;
+
+	} else if ( META_BACK_CONN_INITED( msc ) ) {
+		assert( msc->msc_ld != NULL );
+		rs->sr_err = LDAP_SUCCESS;
+		do_return = 1;
+
+	} else {
+		/*
+		 * creating...
+		 */
+		META_BACK_CONN_CREATING_SET( msc );
+	}
+
+	if ( dolock ) {
+		ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
+	}
+
+	if ( do_return ) {
+		if ( rs->sr_err != LDAP_SUCCESS
+			&& op->o_conn
+			&& ( sendok & LDAP_BACK_SENDERR ) )
+		{
+			send_ldap_result( op, rs );
+		}
+
+		return rs->sr_err;
+	}
+
+	assert( msc->msc_ld == NULL );
+       
+	/*
+	 * Attempts to initialize the connection to the target ds
+	 */
+	ldap_pvt_thread_mutex_lock( &mt->mt_uri_mutex );
+	rs->sr_err = ldap_initialize( &msc->msc_ld, mt->mt_uri );
+#ifdef HAVE_TLS
+	is_ldaps = ldap_is_ldaps_url( mt->mt_uri );
+#endif /* HAVE_TLS */
+	ldap_pvt_thread_mutex_unlock( &mt->mt_uri_mutex );
+	if ( rs->sr_err != LDAP_SUCCESS ) {
+		goto error_return;
+	}
+
+	/*
+	 * Set LDAP version. This will always succeed: If the client
+	 * bound with a particular version, then so can we.
+	 */
+	if ( mt->mt_version != 0 ) {
+		version = mt->mt_version;
+
+	} else if ( op->o_conn->c_protocol != 0 ) {
+		version = op->o_conn->c_protocol;
+
+	} else {
+		version = LDAP_VERSION3;
+	}
+	ldap_set_option( msc->msc_ld, LDAP_OPT_PROTOCOL_VERSION, &version );
+	ldap_set_urllist_proc( msc->msc_ld, mt->mt_urllist_f, mt->mt_urllist_p );
+
+	/* automatically chase referrals ("chase-referrals [{yes|no}]" statement) */
+	ldap_set_option( msc->msc_ld, LDAP_OPT_REFERRALS,
+		META_BACK_TGT_CHASE_REFERRALS( mt ) ? LDAP_OPT_ON : LDAP_OPT_OFF );
+
+	slap_client_keepalive(msc->msc_ld, &mt->mt_tls.sb_keepalive);
+
+	if ( mt->mt_tls.sb_tcp_user_timeout > 0 ) {
+		ldap_set_option( msc->msc_ld, LDAP_OPT_TCP_USER_TIMEOUT,
+				&mt->mt_tls.sb_tcp_user_timeout );
+	}
+
+
+
+#ifdef HAVE_TLS
+	{
+		slap_bindconf *sb = NULL;
+
+		if ( ispriv ) {
+			sb = &mt->mt_idassert.si_bc;
+		} else {
+			sb = &mt->mt_tls;
+		}
+
+		bindconf_tls_set( sb, msc->msc_ld );
+
+		if ( !is_ldaps ) {
+			if ( META_BACK_TGT_USE_TLS( mt )
+				|| ( op->o_conn->c_is_tls && META_BACK_TGT_PROPAGATE_TLS( mt ) ) )
+			{
+				do_start_tls = 1;
+			}
+		}
+	}
+
+	/* start TLS ("tls [try-]{start|propagate}" statement) */
+	if ( do_start_tls ) {
+#ifdef SLAP_STARTTLS_ASYNCHRONOUS
+		/*
+		 * use asynchronous StartTLS; in case, chase referral
+		 * FIXME: OpenLDAP does not return referral on StartTLS yet
+		 */
+		int		msgid;
+
+		rs->sr_err = ldap_start_tls( msc->msc_ld, NULL, NULL, &msgid );
+		if ( rs->sr_err == LDAP_SUCCESS ) {
+			LDAPMessage	*res = NULL;
+			int		rc, nretries = mt->mt_nretries;
+			struct timeval	tv;
+
+			LDAP_BACK_TV_SET( &tv );
+
+retry:;
+			rc = ldap_result( msc->msc_ld, msgid, LDAP_MSG_ALL, &tv, &res );
+			switch ( rc ) {
+			case -1:
+				rs->sr_err = LDAP_UNAVAILABLE;
+				rs->sr_text = "Remote server down";
+				break;
+
+			case 0:
+				if ( nretries != 0 ) {
+					if ( nretries > 0 ) {
+						nretries--;
+					}
+					LDAP_BACK_TV_SET( &tv );
+					goto retry;
+				}
+				rs->sr_err = LDAP_OTHER;
+				rs->sr_text = "Timeout, no more retries";
+				break;
+
+			default:
+				/* only touch when activity actually took place... */
+				if ( mi->mi_idle_timeout != 0 && msc->msc_time < op->o_time ) {
+					msc->msc_time = op->o_time;
+				}
+				break;
+			}
+
+			if ( rc == LDAP_RES_EXTENDED ) {
+				struct berval	*data = NULL;
+
+				/* NOTE: right now, data is unused, so don't get it */
+				rs->sr_err = ldap_parse_extended_result( msc->msc_ld,
+					res, NULL, NULL /* &data */ , 0 );
+				if ( rs->sr_err == LDAP_SUCCESS ) {
+					int		err;
+
+					/* FIXME: matched? referrals? response controls? */
+					rs->sr_err = ldap_parse_result( msc->msc_ld,
+						res, &err, NULL, NULL, NULL, NULL, 1 );
+					res = NULL;
+
+					if ( rs->sr_err == LDAP_SUCCESS ) {
+						rs->sr_err = err;
+					}
+					rs->sr_err = slap_map_api2result( rs );
+					
+					/* FIXME: in case a referral 
+					 * is returned, should we try
+					 * using it instead of the 
+					 * configured URI? */
+					if ( rs->sr_err == LDAP_SUCCESS ) {
+						rs->sr_err = ldap_install_tls( msc->msc_ld );
+
+					} else if ( rs->sr_err == LDAP_REFERRAL ) {
+						/* FIXME: LDAP_OPERATIONS_ERROR? */
+						rs->sr_err = LDAP_OTHER;
+						rs->sr_text = "Unwilling to chase referral "
+							"returned by Start TLS exop";
+					}
+
+					if ( data ) {
+						ber_bvfree( data );
+					}
+				}
+
+			} else {
+				rs->sr_err = LDAP_OTHER;
+				rs->sr_text = "Unknown response to StartTLS request :"
+					" an ExtendedResponse is expected";
+			}
+
+			if ( res != NULL ) {
+				ldap_msgfree( res );
+			}
+		}
+#else /* ! SLAP_STARTTLS_ASYNCHRONOUS */
+		/*
+		 * use synchronous StartTLS
+		 */
+		rs->sr_err = ldap_start_tls_s( msc->msc_ld, NULL, NULL );
+#endif /* ! SLAP_STARTTLS_ASYNCHRONOUS */
+
+		/* if StartTLS is requested, only attempt it if the URL
+		 * is not "ldaps://"; this may occur not only in case
+		 * of misconfiguration, but also when used in the chain 
+		 * overlay, where the "uri" can be parsed out of a referral */
+		if ( rs->sr_err == LDAP_SERVER_DOWN
+			|| ( rs->sr_err != LDAP_SUCCESS
+				&& META_BACK_TGT_TLS_CRITICAL( mt ) ) )
+		{
+
+#ifdef DEBUG_205
+			Debug( LDAP_DEBUG_ANY,
+				"### %s meta_back_init_one_conn(TLS) "
+				"ldap_unbind_ext[%d] ld=%p\n",
+				op->o_log_prefix, candidate,
+				(void *)msc->msc_ld );
+#endif /* DEBUG_205 */
+
+			/* need to trash a failed Start TLS */
+			meta_clear_one_candidate( op, mc, candidate );
+			goto error_return;
+		}
+	}
+#endif /* HAVE_TLS */
+
+	/*
+	 * Set the network timeout if set
+	 */
+	if ( mt->mt_network_timeout != 0 ) {
+		struct timeval	network_timeout;
+
+		network_timeout.tv_usec = 0;
+		network_timeout.tv_sec = mt->mt_network_timeout;
+
+		ldap_set_option( msc->msc_ld, LDAP_OPT_NETWORK_TIMEOUT,
+				(void *)&network_timeout );
+	}
+
+	/*
+	 * If the connection DN is not null, an attempt to rewrite it is made
+	 */
+
+	if ( ispriv ) {
+		if ( !BER_BVISNULL( &mt->mt_idassert_authcDN ) ) {
+			ber_bvreplace( &msc->msc_bound_ndn, &mt->mt_idassert_authcDN );
+			if ( !BER_BVISNULL( &mt->mt_idassert_passwd ) ) {
+				if ( !BER_BVISNULL( &msc->msc_cred ) ) {
+					memset( msc->msc_cred.bv_val, 0,
+						msc->msc_cred.bv_len );
+				}
+				ber_bvreplace( &msc->msc_cred, &mt->mt_idassert_passwd );
+			}
+			LDAP_BACK_CONN_ISIDASSERT_SET( msc );
+
+		} else {
+			ber_bvreplace( &msc->msc_bound_ndn, &slap_empty_bv );
+		}
+
+	} else {
+		if ( !BER_BVISNULL( &msc->msc_cred ) ) {
+			memset( msc->msc_cred.bv_val, 0, msc->msc_cred.bv_len );
+			ber_memfree_x( msc->msc_cred.bv_val, NULL );
+			BER_BVZERO( &msc->msc_cred );
+		}
+		if ( !BER_BVISNULL( &msc->msc_bound_ndn ) ) {
+			ber_memfree_x( msc->msc_bound_ndn.bv_val, NULL );
+			BER_BVZERO( &msc->msc_bound_ndn );
+		}
+		if ( !BER_BVISEMPTY( &op->o_ndn )
+			&& SLAP_IS_AUTHZ_BACKEND( op )
+			&& isauthz )
+		{
+			dc.target = mt;
+			dc.conn = op->o_conn;
+			dc.rs = rs;
+			dc.ctx = "bindDN";
+		
+			/*
+			 * Rewrite the bind dn if needed
+			 */
+			if ( ldap_back_dn_massage( &dc, &op->o_conn->c_dn,
+						&msc->msc_bound_ndn ) )
+			{
+
+#ifdef DEBUG_205
+				Debug( LDAP_DEBUG_ANY,
+					"### %s meta_back_init_one_conn(rewrite) "
+					"ldap_unbind_ext[%d] ld=%p\n",
+					op->o_log_prefix, candidate,
+					(void *)msc->msc_ld );
+#endif /* DEBUG_205 */
+
+				/* need to trash a connection not fully established */
+				meta_clear_one_candidate( op, mc, candidate );
+				goto error_return;
+			}
+			
+			/* copy the DN if needed */
+			if ( msc->msc_bound_ndn.bv_val == op->o_conn->c_dn.bv_val ) {
+				ber_dupbv( &msc->msc_bound_ndn, &op->o_conn->c_dn );
+			}
+
+			assert( !BER_BVISNULL( &msc->msc_bound_ndn ) );
+
+		} else {
+			ber_dupbv( &msc->msc_bound_ndn, (struct berval *)&slap_empty_bv );
+		}
+	}
+
+	assert( !BER_BVISNULL( &msc->msc_bound_ndn ) );
+
+error_return:;
+	if ( dolock ) {
+		ldap_pvt_thread_mutex_lock( &mi->mi_conninfo.lai_mutex );
+	}
+	META_BACK_CONN_CREATING_CLEAR( msc );
+	if ( rs->sr_err == LDAP_SUCCESS ) {
+		/*
+		 * Sets a cookie for the rewrite session
+		 */
+		( void )rewrite_session_init( mt->mt_rwmap.rwm_rw, op->o_conn );
+		META_BACK_CONN_INITED_SET( msc );
+	}
+	if ( dolock ) {
+		ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
+	}
+
+	if ( rs->sr_err != LDAP_SUCCESS ) {
+		/* Get the error message and print it in TRACE mode */
+		if ( LogTest( LDAP_DEBUG_TRACE ) ) {
+			Log( LDAP_DEBUG_TRACE, ldap_syslog_level, "%s: meta_back_init_one_conn[%d] failed err=%d text=%s\n",
+				op->o_log_prefix, candidate, rs->sr_err, rs->sr_text );
+		}
+
+		rs->sr_err = slap_map_api2result( rs );
+		if ( sendok & LDAP_BACK_SENDERR ) {
+			send_ldap_result( op, rs );
+		}
+	}
+
+	return rs->sr_err;
+}
+
+/*
+ * meta_back_retry
+ * 
+ * Retries one connection
+ */
+int
+meta_back_retry(
+	Operation		*op,
+	SlapReply		*rs,
+	metaconn_t		**mcp,
+	int			candidate,
+	ldap_back_send_t	sendok )
+{
+	metainfo_t		*mi = ( metainfo_t * )op->o_bd->be_private;
+	metatarget_t		*mt = mi->mi_targets[ candidate ];
+	metaconn_t		*mc = *mcp;
+	metasingleconn_t	*msc = &mc->mc_conns[ candidate ];
+	int			rc = LDAP_UNAVAILABLE,
+				binding,
+				quarantine = 1;
+
+	ldap_pvt_thread_mutex_lock( &mi->mi_conninfo.lai_mutex );
+
+	assert( !META_BACK_CONN_CREATING( msc ) );
+	binding = LDAP_BACK_CONN_BINDING( msc );
+	LDAP_BACK_CONN_BINDING_CLEAR( msc );
+
+	assert( mc->mc_refcnt > 0 );
+	if ( mc->mc_refcnt == 1 ) {
+		struct berval save_cred;
+
+		if ( LogTest( LDAP_DEBUG_ANY ) ) {
+			/* this lock is required; however,
+			 * it's invoked only when logging is on */
+			ldap_pvt_thread_mutex_lock( &mt->mt_uri_mutex );
+			Debug(LDAP_DEBUG_ANY,
+			      "%s meta_back_retry[%d]: retrying URI=\"%s\" DN=\"%s\".\n",
+			      op->o_log_prefix, candidate, mt->mt_uri,
+			      BER_BVISNULL(&msc->msc_bound_ndn) ? "" : msc->msc_bound_ndn.bv_val );
+			ldap_pvt_thread_mutex_unlock( &mt->mt_uri_mutex );
+		}
+
+		/* save credentials, if any, for later use;
+		 * meta_clear_one_candidate() would free them */
+		save_cred = msc->msc_cred;
+		BER_BVZERO( &msc->msc_cred );
+
+		meta_clear_one_candidate( op, mc, candidate );
+		LDAP_BACK_CONN_ISBOUND_CLEAR( msc );
+
+		( void )rewrite_session_delete( mt->mt_rwmap.rwm_rw, op->o_conn );
+
+		/* mc here must be the regular mc, reset and ready for init */
+		rc = meta_back_init_one_conn( op, rs, mc, candidate,
+			LDAP_BACK_CONN_ISPRIV( mc ), sendok, 0 );
+
+		/* restore credentials, if any and if needed;
+		 * meta_back_init_one_conn() restores msc_bound_ndn, if any;
+		 * if no msc_bound_ndn is restored, destroy credentials */
+		if ( !BER_BVISNULL( &msc->msc_bound_ndn )
+			&& BER_BVISNULL( &msc->msc_cred ) )
+		{
+			msc->msc_cred = save_cred;
+
+		} else if ( !BER_BVISNULL( &save_cred ) ) {
+			memset( save_cred.bv_val, 0, save_cred.bv_len );
+			ber_memfree_x( save_cred.bv_val, NULL );
+		}
+
+		/* restore the "binding" flag, in case */
+		if ( binding ) {
+			LDAP_BACK_CONN_BINDING_SET( msc );
+		}
+
+		if ( rc == LDAP_SUCCESS ) {
+			quarantine = 0;
+			LDAP_BACK_CONN_BINDING_SET( msc ); binding = 1;
+			rc = meta_back_single_dobind( op, rs, mcp, candidate,
+				sendok, mt->mt_nretries, 0 );
+
+			Debug( LDAP_DEBUG_ANY,
+				"%s meta_back_retry[%d]: "
+				"meta_back_single_dobind=%d\n",
+				op->o_log_prefix, candidate, rc );
+			if ( rc == LDAP_SUCCESS ) {
+				if ( !BER_BVISNULL( &msc->msc_bound_ndn ) &&
+					!BER_BVISEMPTY( &msc->msc_bound_ndn ) )
+				{
+					LDAP_BACK_CONN_ISBOUND_SET( msc );
+
+				} else {
+					LDAP_BACK_CONN_ISANON_SET( msc );
+				}
+
+				/* when bound, dispose of the "binding" flag */
+				if ( binding ) {
+					LDAP_BACK_CONN_BINDING_CLEAR( msc );
+				}
+			}
+		}
+
+#if 0	/* ITS#7591, following stmt drops needed result msgs */
+		/* don't send twice */
+		sendok &= ~LDAP_BACK_SENDERR;
+#endif
+	}
+
+	if ( rc != LDAP_SUCCESS ) {
+		SlapReply		*candidates = meta_back_candidates_get( op );
+
+		candidates[ candidate ].sr_err = rc;
+
+		if ( *mcp != NULL ) {
+			if ( mc->mc_refcnt == 1 ) {
+				if ( binding ) {
+					LDAP_BACK_CONN_BINDING_CLEAR( msc );
+				}
+				(void)meta_clear_one_candidate( op, mc, candidate );
+			}
+
+			LDAP_BACK_CONN_TAINTED_SET( mc );
+			/* only release if mandatory; otherwise
+			 * let the caller do what's best before
+			 * releasing */
+			if ( META_BACK_ONERR_STOP( mi ) ) {
+				meta_back_release_conn_lock( mi, mc, 0 );
+				*mcp = NULL;
+
+			} else {
+#if META_BACK_PRINT_CONNTREE > 0
+				meta_back_print_conntree( mi, ">>> meta_back_retry" );
+#endif /* META_BACK_PRINT_CONNTREE */
+
+				/* FIXME: could be done better, reworking meta_back_release_conn_lock() */
+				if ( LDAP_BACK_PCONN_ISPRIV( mc ) ) {
+					if ( mc->mc_q.tqe_prev != NULL ) {
+						assert( LDAP_BACK_CONN_CACHED( mc ) );
+						assert( mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num > 0 );
+						LDAP_TAILQ_REMOVE( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_priv,
+							mc, mc_q );
+						mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num--;
+						LDAP_TAILQ_ENTRY_INIT( mc, mc_q );
+
+					} else {
+						assert( !LDAP_BACK_CONN_CACHED( mc ) );
+					}
+
+				} else {
+					/* FIXME: check if in tree, for consistency? */
+					(void)ldap_tavl_delete( &mi->mi_conninfo.lai_tree,
+						( caddr_t )mc, meta_back_conndnmc_cmp );
+				}
+				LDAP_BACK_CONN_CACHED_CLEAR( mc );
+
+#if META_BACK_PRINT_CONNTREE > 0
+				meta_back_print_conntree( mi, "<<< meta_back_retry" );
+#endif /* META_BACK_PRINT_CONNTREE */
+			}
+		}
+
+		if ( sendok & LDAP_BACK_SENDERR ) {
+			rs->sr_err = rc;
+			rs->sr_text = "Unable to retry";
+			send_ldap_result( op, rs );
+		}
+	}
+
+	if ( quarantine && META_BACK_TGT_QUARANTINE( mt ) ) {
+		meta_back_quarantine( op, rs, candidate );
+	}
+
+	ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
+
+	return rc == LDAP_SUCCESS ? 1 : 0;
+}
+
+/*
+ * callback for unique candidate selection
+ */
+static int
+meta_back_conn_cb( Operation *op, SlapReply *rs )
+{
+	assert( op->o_tag == LDAP_REQ_SEARCH );
+
+	switch ( rs->sr_type ) {
+	case REP_SEARCH:
+		((long *)op->o_callback->sc_private)[0] = (long)op->o_private;
+		break;
+
+	case REP_SEARCHREF:
+	case REP_RESULT:
+		break;
+
+	default:
+		return rs->sr_err;
+	}
+
+	return 0;
+}
+
+
+static int
+meta_back_get_candidate(
+	Operation	*op,
+	SlapReply	*rs,
+	struct berval	*ndn )
+{
+	metainfo_t	*mi = ( metainfo_t * )op->o_bd->be_private;
+	long		candidate;
+
+	/*
+	 * tries to get a unique candidate
+	 * (takes care of default target)
+	 */
+	candidate = meta_back_select_unique_candidate( mi, ndn );
+
+	/*
+	 * if any is found, inits the connection
+	 */
+	if ( candidate == META_TARGET_NONE ) {
+		rs->sr_err = LDAP_NO_SUCH_OBJECT;
+		rs->sr_text = "No suitable candidate target found";
+
+	} else if ( candidate == META_TARGET_MULTIPLE ) {
+		Operation	op2 = *op;
+		SlapReply	rs2 = { REP_RESULT };
+		slap_callback	cb2 = { 0 };
+		int		rc;
+
+		/* try to get a unique match for the request ndn
+		 * among the multiple candidates available */
+		op2.o_tag = LDAP_REQ_SEARCH;
+		op2.o_req_dn = *ndn;
+		op2.o_req_ndn = *ndn;
+		op2.ors_scope = LDAP_SCOPE_BASE;
+		op2.ors_deref = LDAP_DEREF_NEVER;
+		op2.ors_attrs = slap_anlist_no_attrs;
+		op2.ors_attrsonly = 0;
+		op2.ors_limit = NULL;
+		op2.ors_slimit = 1;
+		op2.ors_tlimit = SLAP_NO_LIMIT;
+
+		op2.ors_filter = (Filter *)slap_filter_objectClass_pres;
+		op2.ors_filterstr = *slap_filterstr_objectClass_pres;
+
+		op2.o_callback = &cb2;
+		cb2.sc_response = meta_back_conn_cb;
+		cb2.sc_private = (void *)&candidate;
+
+		rc = op->o_bd->be_search( &op2, &rs2 );
+
+		switch ( rs2.sr_err ) {
+		case LDAP_SUCCESS:
+		default:
+			rs->sr_err = rs2.sr_err;
+			break;
+
+		case LDAP_SIZELIMIT_EXCEEDED:
+			/* if multiple candidates can serve the operation,
+			 * and a default target is defined, and it is
+			 * a candidate, try using it (FIXME: YMMV) */
+			if ( mi->mi_defaulttarget != META_DEFAULT_TARGET_NONE
+				&& meta_back_is_candidate( mi->mi_targets[ mi->mi_defaulttarget ],
+						ndn, op->o_tag == LDAP_REQ_SEARCH ? op->ors_scope : LDAP_SCOPE_BASE ) )
+			{
+				candidate = mi->mi_defaulttarget;
+				rs->sr_err = LDAP_SUCCESS;
+				rs->sr_text = NULL;
+
+			} else {
+				rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
+				rs->sr_text = "Unable to select unique candidate target";
+			}
+			break;
+		}
+
+	} else {
+		rs->sr_err = LDAP_SUCCESS;
+	}
+
+	return candidate;
+}
+
+static void	*meta_back_candidates_dummy;
+
+static void
+meta_back_candidates_keyfree(
+	void		*key,
+	void		*data )
+{
+	metacandidates_t	*mc = (metacandidates_t *)data;
+
+	ber_memfree_x( mc->mc_candidates, NULL );
+	ber_memfree_x( data, NULL );
+}
+
+SlapReply *
+meta_back_candidates_get( Operation *op )
+{
+	metainfo_t		*mi = ( metainfo_t * )op->o_bd->be_private;
+	metacandidates_t	*mc;
+
+	if ( op->o_threadctx ) {
+		void		*data = NULL;
+
+		ldap_pvt_thread_pool_getkey( op->o_threadctx,
+				&meta_back_candidates_dummy, &data, NULL );
+		mc = (metacandidates_t *)data;
+
+	} else {
+		mc = mi->mi_candidates;
+	}
+
+	if ( mc == NULL ) {
+		mc = ch_calloc( sizeof( metacandidates_t ), 1 );
+		mc->mc_ntargets = mi->mi_ntargets;
+		mc->mc_candidates = ch_calloc( sizeof( SlapReply ), mc->mc_ntargets );
+		if ( op->o_threadctx ) {
+			void		*data = NULL;
+
+			data = (void *)mc;
+			ldap_pvt_thread_pool_setkey( op->o_threadctx,
+					&meta_back_candidates_dummy, data,
+					meta_back_candidates_keyfree,
+					NULL, NULL );
+
+		} else {
+			mi->mi_candidates = mc;
+		}
+
+	} else if ( mc->mc_ntargets < mi->mi_ntargets ) {
+		/* NOTE: in the future, may want to allow back-config
+		 * to add/remove targets from back-meta... */
+		mc->mc_candidates = ch_realloc( mc->mc_candidates,
+				sizeof( SlapReply ) * mi->mi_ntargets );
+		memset( &mc->mc_candidates[ mc->mc_ntargets ], 0,
+			sizeof( SlapReply ) * ( mi->mi_ntargets - mc->mc_ntargets ) );
+		mc->mc_ntargets = mi->mi_ntargets;
+	}
+
+	return mc->mc_candidates;
+}
+
+/*
+ * meta_back_getconn
+ * 
+ * Prepares the connection structure
+ * 
+ * RATIONALE:
+ *
+ * - determine what DN is being requested:
+ *
+ *	op	requires candidate	checks
+ *
+ *	add	unique			parent of o_req_ndn
+ *	bind	unique^*[/all]		o_req_ndn [no check]
+ *	compare	unique^+		o_req_ndn
+ *	delete	unique			o_req_ndn
+ *	modify	unique			o_req_ndn
+ *	search	any			o_req_ndn
+ *	modrdn	unique[, unique]	o_req_ndn[, orr_nnewSup]
+ *
+ * - for ops that require the candidate to be unique, in case of multiple
+ *   occurrences an internal search with sizeLimit=1 is performed
+ *   if a unique candidate can actually be determined.  If none is found,
+ *   the operation aborts; if multiple are found, the default target
+ *   is used if defined and candidate; otherwise the operation aborts.
+ *
+ * *^note: actually, the bind operation is handled much like a search;
+ *   i.e. the bind is broadcast to all candidate targets.
+ *
+ * +^note: actually, the compare operation is handled much like a search;
+ *   i.e. the compare is broadcast to all candidate targets, while checking
+ *   that exactly none (noSuchObject) or one (TRUE/FALSE/UNDEFINED) is
+ *   returned.
+ */
+metaconn_t *
+meta_back_getconn(
+       	Operation 		*op,
+	SlapReply		*rs,
+	int 			*candidate,
+	ldap_back_send_t	sendok )
+{
+	metainfo_t	*mi = ( metainfo_t * )op->o_bd->be_private;
+	metaconn_t	*mc = NULL,
+			mc_curr = {{ 0 }};
+	int		cached = META_TARGET_NONE,
+			i = META_TARGET_NONE,
+			err = LDAP_SUCCESS,
+			new_conn = 0,
+			ncandidates = 0;
+
+
+	meta_op_type	op_type = META_OP_REQUIRE_SINGLE;
+	enum		{
+		META_DNTYPE_ENTRY,
+		META_DNTYPE_PARENT,
+		META_DNTYPE_NEWPARENT
+	}		dn_type = META_DNTYPE_ENTRY;
+	struct berval	ndn = op->o_req_ndn,
+			pndn;
+
+	SlapReply	*candidates = meta_back_candidates_get( op );
+
+	/* Internal searches are privileged and shared. So is root. */
+	if ( ( !BER_BVISEMPTY( &op->o_ndn ) && META_BACK_PROXYAUTHZ_ALWAYS( mi ) )
+		|| ( BER_BVISEMPTY( &op->o_ndn ) && META_BACK_PROXYAUTHZ_ANON( mi ) )
+		|| op->o_do_not_cache || be_isroot( op ) )
+	{
+		LDAP_BACK_CONN_ISPRIV_SET( &mc_curr );
+		mc_curr.mc_local_ndn = op->o_bd->be_rootndn;
+		LDAP_BACK_PCONN_ROOTDN_SET( &mc_curr, op );
+
+	} else if ( BER_BVISEMPTY( &op->o_ndn ) && META_BACK_PROXYAUTHZ_NOANON( mi ) )
+	{
+		LDAP_BACK_CONN_ISANON_SET( &mc_curr );
+		BER_BVSTR( &mc_curr.mc_local_ndn, "" );
+		LDAP_BACK_PCONN_ANON_SET( &mc_curr, op );
+
+	} else {
+		mc_curr.mc_local_ndn = op->o_ndn;
+
+		/* Explicit binds must not be shared */
+		if ( !BER_BVISEMPTY( &op->o_ndn )
+			|| op->o_tag == LDAP_REQ_BIND
+			|| SLAP_IS_AUTHZ_BACKEND( op ) )
+		{
+			mc_curr.mc_conn = op->o_conn;
+	
+		} else {
+			LDAP_BACK_CONN_ISANON_SET( &mc_curr );
+			LDAP_BACK_PCONN_ANON_SET( &mc_curr, op );
+		}
+	}
+
+	/* Explicit Bind requests always get their own conn */
+	if ( sendok & LDAP_BACK_BINDING ) {
+		mc_curr.mc_conn = op->o_conn;
+
+	} else {
+		/* Searches for a metaconn in the avl tree */
+retry_lock:;
+		ldap_pvt_thread_mutex_lock( &mi->mi_conninfo.lai_mutex );
+		if ( LDAP_BACK_PCONN_ISPRIV( &mc_curr ) ) {
+			/* lookup a conn that's not binding */
+			LDAP_TAILQ_FOREACH( mc,
+				&mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( &mc_curr ) ].mic_priv,
+				mc_q )
+			{
+				if ( !LDAP_BACK_CONN_BINDING( mc ) && mc->mc_refcnt == 0 ) {
+					break;
+				}
+			}
+
+			if ( mc != NULL ) {
+				/* move to tail of queue */
+				if ( mc != LDAP_TAILQ_LAST( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_priv,
+					mc_conn_priv_q ) )
+				{
+					LDAP_TAILQ_REMOVE( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_priv,
+						mc, mc_q );
+					LDAP_TAILQ_ENTRY_INIT( mc, mc_q );
+					LDAP_TAILQ_INSERT_TAIL( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_priv,
+						mc, mc_q );
+				}
+
+			} else if ( !LDAP_BACK_USE_TEMPORARIES( mi )
+				&& mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( &mc_curr ) ].mic_num == mi->mi_conn_priv_max )
+			{
+				mc = LDAP_TAILQ_FIRST( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( &mc_curr ) ].mic_priv );
+			}
+			
+
+		} else {
+			mc = (metaconn_t *)ldap_tavl_find( mi->mi_conninfo.lai_tree,
+				(caddr_t)&mc_curr, meta_back_conndn_cmp );
+		}
+
+		if ( mc ) {
+			/* catch taint errors */
+			assert( !LDAP_BACK_CONN_TAINTED( mc ) );
+
+			/* Don't reuse connections while they're still binding
+			 * NOTE: only makes sense for binds */
+			if ( LDAP_BACK_CONN_BINDING( mc ) ) {
+				if ( !LDAP_BACK_USE_TEMPORARIES( mi ) ) {
+					ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
+
+					ldap_pvt_thread_yield();
+					goto retry_lock;
+				}
+
+				/* release conn, and create a temporary */
+				mc = NULL;
+
+			} else {
+				if ( mc->mc_refcnt == 0 && (( mi->mi_conn_ttl != 0 && op->o_time > mc->mc_create_time + mi->mi_conn_ttl )
+					|| ( mi->mi_idle_timeout != 0 && op->o_time > mc->mc_time + mi->mi_idle_timeout )) )
+				{
+#if META_BACK_PRINT_CONNTREE > 0
+					meta_back_print_conntree( mi,
+						">>> meta_back_getconn(expired)" );
+#endif /* META_BACK_PRINT_CONNTREE */
+
+					/* don't let anyone else use this expired connection */
+					if ( LDAP_BACK_PCONN_ISPRIV( mc ) ) {
+						if ( mc->mc_q.tqe_prev != NULL ) {
+							assert( LDAP_BACK_CONN_CACHED( mc ) );
+							assert( mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num > 0 );
+							LDAP_TAILQ_REMOVE( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_priv,
+								mc, mc_q );
+							mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num--;
+							LDAP_TAILQ_ENTRY_INIT( mc, mc_q );
+
+						} else {
+							assert( !LDAP_BACK_CONN_CACHED( mc ) );
+						}
+
+					} else {
+						(void)ldap_tavl_delete( &mi->mi_conninfo.lai_tree,
+							(caddr_t)mc, meta_back_conndnmc_cmp );
+					}
+
+#if META_BACK_PRINT_CONNTREE > 0
+					meta_back_print_conntree( mi,
+						"<<< meta_back_getconn(expired)" );
+#endif /* META_BACK_PRINT_CONNTREE */
+					LDAP_BACK_CONN_TAINTED_SET( mc );
+					LDAP_BACK_CONN_CACHED_CLEAR( mc );
+
+					if ( LogTest( LDAP_DEBUG_TRACE ) ) {
+						char buf[STRLENOF("4294967295U") + 1] = { 0 };
+						mi->mi_ldap_extra->connid2str( &mc->mc_base, buf, sizeof(buf) );
+
+						Debug( LDAP_DEBUG_TRACE,
+							"%s meta_back_getconn: mc=%p conn=%s expired (tainted).\n",
+							op->o_log_prefix, (void *)mc, buf );
+					}
+				}
+
+				mc->mc_refcnt++;
+			}
+		}
+		ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
+	}
+
+	switch ( op->o_tag ) {
+	case LDAP_REQ_ADD:
+		/* if we go to selection, the entry must not exist,
+		 * and we must be able to resolve the parent */
+		dn_type = META_DNTYPE_PARENT;
+		dnParent( &ndn, &pndn );
+		break;
+
+	case LDAP_REQ_MODRDN:
+		/* if nnewSuperior is not NULL, it must resolve
+		 * to the same candidate as the req_ndn */
+		if ( op->orr_nnewSup ) {
+			dn_type = META_DNTYPE_NEWPARENT;
+		}
+		break;
+
+	case LDAP_REQ_BIND:
+		/* if bound as rootdn, the backend must bind to all targets
+		 * with the administrative identity
+		 * (unless pseoudoroot-bind-defer is TRUE) */
+		if ( op->orb_method == LDAP_AUTH_SIMPLE && be_isroot_pw( op ) ) {
+			op_type = META_OP_REQUIRE_ALL;
+		}
+		break;
+
+	case LDAP_REQ_COMPARE:
+	case LDAP_REQ_DELETE:
+	case LDAP_REQ_MODIFY:
+		/* just a unique candidate */
+		break;
+
+	case LDAP_REQ_SEARCH:
+		/* allow multiple candidates for the searchBase */
+		op_type = META_OP_ALLOW_MULTIPLE;
+		break;
+
+	default:
+		/* right now, just break (exop?) */
+		break;
+	}
+
+	/*
+	 * require all connections ...
+	 */
+	if ( op_type == META_OP_REQUIRE_ALL ) {
+
+		/* Looks like we didn't get a bind. Open a new session... */
+		if ( mc == NULL ) {
+			assert( new_conn == 0 );
+			mc = metaconn_alloc( op );
+			mc->mc_conn = mc_curr.mc_conn;
+			ber_dupbv( &mc->mc_local_ndn, &mc_curr.mc_local_ndn );
+			new_conn = 1;
+			if ( sendok & LDAP_BACK_BINDING ) {
+				LDAP_BACK_CONN_BINDING_SET( mc );
+			}
+			if ( LDAP_BACK_CONN_ISPRIV( &mc_curr ) ) {
+				LDAP_BACK_CONN_ISPRIV_SET( mc );
+
+			} else if ( LDAP_BACK_CONN_ISANON( &mc_curr ) ) {
+				LDAP_BACK_CONN_ISANON_SET( mc );
+			}
+
+		} else if ( 0 ) {
+			/* TODO: if any of the connections is binding,
+			 * release mc and create a new one */
+		}
+
+		for ( i = 0; i < mi->mi_ntargets; i++ ) {
+			/*
+			 * The target is activated; if needed, it is
+			 * also init'd
+			 */
+			candidates[ i ].sr_err = meta_back_init_one_conn( op,
+				rs, mc, i, LDAP_BACK_CONN_ISPRIV( &mc_curr ),
+				LDAP_BACK_DONTSEND, !new_conn );
+			if ( candidates[ i ].sr_err == LDAP_SUCCESS ) {
+				if ( new_conn && ( sendok & LDAP_BACK_BINDING ) ) {
+					LDAP_BACK_CONN_BINDING_SET( &mc->mc_conns[ i ] );
+				}
+				META_CANDIDATE_SET( &candidates[ i ] );
+				ncandidates++;
+	
+			} else {
+				
+				/*
+				 * FIXME: in case one target cannot
+				 * be init'd, should the other ones
+				 * be tried?
+				 */
+				META_CANDIDATE_RESET( &candidates[ i ] );
+				err = candidates[ i ].sr_err;
+				continue;
+			}
+		}
+
+		if ( ncandidates == 0 ) {
+			if ( new_conn ) {
+				mc->mc_refcnt = 0;
+				meta_back_conn_free( mc );
+
+			} else {
+				meta_back_release_conn( mi, mc );
+			}
+
+			rs->sr_err = LDAP_NO_SUCH_OBJECT;
+			rs->sr_text = "Unable to select valid candidates";
+
+			if ( sendok & LDAP_BACK_SENDERR ) {
+				if ( rs->sr_err == LDAP_NO_SUCH_OBJECT ) {
+					rs->sr_matched = op->o_bd->be_suffix[ 0 ].bv_val;
+				}
+				send_ldap_result( op, rs );
+				rs->sr_matched = NULL;
+			}
+
+			return NULL;
+		}
+
+		goto done;
+	}
+	
+	/*
+	 * looks in cache, if any
+	 */
+	if ( mi->mi_cache.ttl != META_DNCACHE_DISABLED ) {
+		cached = i = meta_dncache_get_target( &mi->mi_cache, &op->o_req_ndn );
+	}
+
+	if ( op_type == META_OP_REQUIRE_SINGLE ) {
+		metatarget_t		*mt = NULL;
+		metasingleconn_t	*msc = NULL;
+
+		int			j;
+
+		for ( j = 0; j < mi->mi_ntargets; j++ ) {
+			META_CANDIDATE_RESET( &candidates[ j ] );
+		}
+
+		/*
+		 * tries to get a unique candidate
+		 * (takes care of default target)
+		 */
+		if ( i == META_TARGET_NONE ) {
+			i = meta_back_get_candidate( op, rs, &ndn );
+
+			if ( rs->sr_err == LDAP_NO_SUCH_OBJECT && dn_type == META_DNTYPE_PARENT ) {
+				i = meta_back_get_candidate( op, rs, &pndn );
+			}
+	
+			if ( i < 0 || rs->sr_err != LDAP_SUCCESS ) {
+				if ( mc != NULL ) {
+					meta_back_release_conn( mi, mc );
+				}
+
+				if ( sendok & LDAP_BACK_SENDERR ) {
+					if ( rs->sr_err == LDAP_NO_SUCH_OBJECT ) {
+						rs->sr_matched = op->o_bd->be_suffix[ 0 ].bv_val;
+					}
+					send_ldap_result( op, rs );
+					rs->sr_matched = NULL;
+				}
+			
+				return NULL;
+			}
+		}
+
+		if ( dn_type == META_DNTYPE_NEWPARENT && meta_back_get_candidate( op, rs, op->orr_nnewSup ) != i )
+		{
+			if ( mc != NULL ) {
+				meta_back_release_conn( mi, mc );
+			}
+
+			rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
+			rs->sr_text = "Cross-target rename not supported";
+			if ( sendok & LDAP_BACK_SENDERR ) {
+				send_ldap_result( op, rs );
+			}
+
+			return NULL;
+		}
+
+		Debug( LDAP_DEBUG_TRACE,
+	"==>meta_back_getconn: got target=%d for ndn=\"%s\" from cache\n",
+				i, op->o_req_ndn.bv_val );
+
+		if ( mc == NULL ) {
+			/* Retries searching for a metaconn in the avl tree
+			 * the reason is that the connection might have been
+			 * created by meta_back_get_candidate() */
+			if ( !( sendok & LDAP_BACK_BINDING ) ) {
+retry_lock2:;
+				ldap_pvt_thread_mutex_lock( &mi->mi_conninfo.lai_mutex );
+				mc = (metaconn_t *)ldap_tavl_find( mi->mi_conninfo.lai_tree,
+					(caddr_t)&mc_curr, meta_back_conndn_cmp );
+				if ( mc != NULL ) {
+					/* catch taint errors */
+					assert( !LDAP_BACK_CONN_TAINTED( mc ) );
+
+					/* Don't reuse connections while they're still binding */
+					if ( META_BACK_CONN_CREATING( &mc->mc_conns[ i ] )
+						|| LDAP_BACK_CONN_BINDING( &mc->mc_conns[ i ] ) )
+					{
+						if ( !LDAP_BACK_USE_TEMPORARIES( mi ) ) {
+							ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
+							ldap_pvt_thread_yield();
+							goto retry_lock2;
+						}
+
+						mc = NULL;
+
+					} else {
+						mc->mc_refcnt++;
+					}
+				}
+				ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
+			}
+
+			/* Looks like we didn't get a bind. Open a new session... */
+			if ( mc == NULL ) {
+				assert( new_conn == 0 );
+				mc = metaconn_alloc( op );
+				mc->mc_conn = mc_curr.mc_conn;
+				ber_dupbv( &mc->mc_local_ndn, &mc_curr.mc_local_ndn );
+				new_conn = 1;
+				if ( sendok & LDAP_BACK_BINDING ) {
+					LDAP_BACK_CONN_BINDING_SET( mc );
+				}
+				if ( LDAP_BACK_CONN_ISPRIV( &mc_curr ) ) {
+					LDAP_BACK_CONN_ISPRIV_SET( mc );
+
+				} else if ( LDAP_BACK_CONN_ISANON( &mc_curr ) ) {
+					LDAP_BACK_CONN_ISANON_SET( mc );
+				}
+			}
+		}
+
+		/*
+		 * Clear all other candidates
+		 */
+		( void )meta_clear_unused_candidates( op, i );
+
+		mt = mi->mi_targets[ i ];
+		msc = &mc->mc_conns[ i ];
+
+		/*
+		 * The target is activated; if needed, it is
+		 * also init'd. In case of error, meta_back_init_one_conn
+		 * sends the appropriate result.
+		 */
+		err = meta_back_init_one_conn( op, rs, mc, i,
+			LDAP_BACK_CONN_ISPRIV( &mc_curr ), sendok, !new_conn );
+		if ( err != LDAP_SUCCESS ) {
+			/*
+			 * FIXME: in case one target cannot
+			 * be init'd, should the other ones
+			 * be tried?
+			 */
+			META_CANDIDATE_RESET( &candidates[ i ] );
+ 			if ( new_conn ) {
+				mc->mc_refcnt = 0;
+				meta_back_conn_free( mc );
+
+			} else {
+				meta_back_release_conn( mi, mc );
+			}
+			return NULL;
+		}
+
+		if ( new_conn && ( sendok & LDAP_BACK_BINDING ) ) {
+			LDAP_BACK_CONN_BINDING_SET( &mc->mc_conns[ i ] );
+		}
+
+		candidates[ i ].sr_err = LDAP_SUCCESS;
+		META_CANDIDATE_SET( &candidates[ i ] );
+		ncandidates++;
+
+		if ( candidate ) {
+			*candidate = i;
+		}
+
+	/*
+	 * if no unique candidate ...
+	 */
+	} else {
+
+		/* Looks like we didn't get a bind. Open a new session... */
+		if ( mc == NULL ) {
+			assert( new_conn == 0 );
+			mc = metaconn_alloc( op );
+			mc->mc_conn = mc_curr.mc_conn;
+			ber_dupbv( &mc->mc_local_ndn, &mc_curr.mc_local_ndn );
+			new_conn = 1;
+			if ( LDAP_BACK_CONN_ISPRIV( &mc_curr ) ) {
+				LDAP_BACK_CONN_ISPRIV_SET( mc );
+
+			} else if ( LDAP_BACK_CONN_ISANON( &mc_curr ) ) {
+				LDAP_BACK_CONN_ISANON_SET( mc );
+			}
+		}
+
+		for ( i = 0; i < mi->mi_ntargets; i++ ) {
+			metatarget_t		*mt = mi->mi_targets[ i ];
+
+			META_CANDIDATE_RESET( &candidates[ i ] );
+
+			if ( i == cached 
+				|| meta_back_is_candidate( mt, &op->o_req_ndn,
+					op->o_tag == LDAP_REQ_SEARCH ? op->ors_scope : LDAP_SCOPE_SUBTREE ) )
+			{
+
+				/*
+				 * The target is activated; if needed, it is
+				 * also init'd
+				 */
+				int lerr = meta_back_init_one_conn( op, rs, mc, i,
+					LDAP_BACK_CONN_ISPRIV( &mc_curr ),
+					LDAP_BACK_DONTSEND, !new_conn );
+				candidates[ i ].sr_err = lerr;
+				if ( lerr == LDAP_SUCCESS ) {
+					META_CANDIDATE_SET( &candidates[ i ] );
+					ncandidates++;
+
+					Debug( LDAP_DEBUG_TRACE, "%s: meta_back_getconn[%d]\n",
+						op->o_log_prefix, i );
+
+				} else if ( lerr == LDAP_UNAVAILABLE && !META_BACK_ONERR_STOP( mi ) ) {
+					META_CANDIDATE_SET( &candidates[ i ] );
+
+					Debug( LDAP_DEBUG_TRACE, "%s: meta_back_getconn[%d] %s\n",
+						op->o_log_prefix, i,
+						mt->mt_isquarantined != LDAP_BACK_FQ_NO ? "quarantined" : "unavailable" );
+
+				} else {
+				
+					/*
+					 * FIXME: in case one target cannot
+					 * be init'd, should the other ones
+					 * be tried?
+					 */
+					if ( new_conn ) {
+						( void )meta_clear_one_candidate( op, mc, i );
+					}
+					/* leave the target candidate, but record the error for later use */
+					err = lerr;
+
+					if ( lerr == LDAP_UNAVAILABLE && mt->mt_isquarantined != LDAP_BACK_FQ_NO ) {
+						Log( LDAP_DEBUG_TRACE, ldap_syslog_level, "%s: meta_back_getconn[%d] quarantined err=%d text=%s\n",
+							op->o_log_prefix, i, lerr, rs->sr_text );
+
+					} else {
+						Log( LDAP_DEBUG_ANY, ldap_syslog, "%s: meta_back_getconn[%d] failed err=%d text=%s\n",
+							op->o_log_prefix, i, lerr, rs->sr_text );
+					}
+
+					if ( META_BACK_ONERR_STOP( mi ) ) {
+						if ( sendok & LDAP_BACK_SENDERR ) {
+							send_ldap_result( op, rs );
+						}
+						if ( new_conn ) {
+							mc->mc_refcnt = 0;
+							meta_back_conn_free( mc );
+
+						} else {
+							meta_back_release_conn( mi, mc );
+						}
+
+						return NULL;
+					}
+
+					continue;
+				}
+
+			} else {
+				if ( new_conn ) {
+					( void )meta_clear_one_candidate( op, mc, i );
+				}
+			}
+		}
+
+		if ( ncandidates == 0 ) {
+			if ( new_conn ) {
+				mc->mc_refcnt = 0;
+				meta_back_conn_free( mc );
+
+			} else {
+				meta_back_release_conn( mi, mc );
+			}
+
+			if ( rs->sr_err == LDAP_SUCCESS ) {
+				rs->sr_err = LDAP_NO_SUCH_OBJECT;
+				rs->sr_text = "Unable to select valid candidates";
+			}
+
+			if ( sendok & LDAP_BACK_SENDERR ) {
+				if ( rs->sr_err == LDAP_NO_SUCH_OBJECT ) {
+					rs->sr_matched = op->o_bd->be_suffix[ 0 ].bv_val;
+				}
+				send_ldap_result( op, rs );
+				rs->sr_matched = NULL;
+			}
+
+			return NULL;
+		}
+	}
+
+done:;
+	/* clear out meta_back_init_one_conn non-fatal errors */
+	rs->sr_err = LDAP_SUCCESS;
+	rs->sr_text = NULL;
+
+	/* touch the timestamp */
+	if ( mi->mi_idle_timeout != 0 ) {
+		mc->mc_time = op->o_time;
+	}
+
+	if ( new_conn ) {
+		if ( mi->mi_conn_ttl ) {
+			mc->mc_create_time = op->o_time;
+		}
+
+		/*
+		 * Inserts the newly created metaconn in the avl tree
+		 */
+		ldap_pvt_thread_mutex_lock( &mi->mi_conninfo.lai_mutex );
+#if META_BACK_PRINT_CONNTREE > 0
+		meta_back_print_conntree( mi, ">>> meta_back_getconn" );
+#endif /* META_BACK_PRINT_CONNTREE */
+
+		err = 0;
+		if ( LDAP_BACK_PCONN_ISPRIV( mc ) ) {
+			if ( mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num < mi->mi_conn_priv_max ) {
+				LDAP_TAILQ_INSERT_TAIL( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_priv, mc, mc_q );
+				mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num++;
+				LDAP_BACK_CONN_CACHED_SET( mc );
+
+			} else {
+				LDAP_BACK_CONN_TAINTED_SET( mc );
+			}
+			rs->sr_err = 0;
+
+		} else if ( !( sendok & LDAP_BACK_BINDING ) ) {
+			err = ldap_tavl_insert( &mi->mi_conninfo.lai_tree, ( caddr_t )mc,
+			       	meta_back_conndn_cmp, meta_back_conndn_dup );
+			LDAP_BACK_CONN_CACHED_SET( mc );
+		}
+
+#if META_BACK_PRINT_CONNTREE > 0
+		meta_back_print_conntree( mi, "<<< meta_back_getconn" );
+#endif /* META_BACK_PRINT_CONNTREE */
+		ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
+
+		if ( !LDAP_BACK_PCONN_ISPRIV( mc ) ) {
+			/*
+			 * Err could be -1 in case a duplicate metaconn is inserted
+			 */
+			switch ( err ) {
+			case 0:
+				break;
+
+			case -1:
+				LDAP_BACK_CONN_CACHED_CLEAR( mc );
+				/* duplicate: free and try to get the newly created one */
+				if ( !( sendok & LDAP_BACK_BINDING ) && !LDAP_BACK_USE_TEMPORARIES( mi ) ) {
+					mc->mc_refcnt = 0;	
+					meta_back_conn_free( mc );
+	
+					new_conn = 0;
+					goto retry_lock;
+				}
+
+				LDAP_BACK_CONN_TAINTED_SET( mc );
+				break;
+
+			default:
+				LDAP_BACK_CONN_CACHED_CLEAR( mc );
+				if ( LogTest( LDAP_DEBUG_ANY ) ) {
+					char buf[STRLENOF("4294967295U") + 1] = { 0 };
+					mi->mi_ldap_extra->connid2str( &mc->mc_base, buf, sizeof(buf) );
+
+					Debug( LDAP_DEBUG_ANY,
+						"%s meta_back_getconn: candidates=%d conn=%s insert failed\n",
+						op->o_log_prefix, ncandidates, buf );
+				}
+	
+				mc->mc_refcnt = 0;	
+				meta_back_conn_free( mc );
+
+				rs->sr_err = LDAP_OTHER;
+				rs->sr_text = "Proxy bind collision";
+				if ( sendok & LDAP_BACK_SENDERR ) {
+					send_ldap_result( op, rs );
+				}
+				return NULL;
+			}
+		}
+
+		if ( LogTest( LDAP_DEBUG_TRACE ) ) {
+			char buf[STRLENOF("4294967295U") + 1] = { 0 };
+			mi->mi_ldap_extra->connid2str( &mc->mc_base, buf, sizeof(buf) );
+
+			Debug( LDAP_DEBUG_TRACE,
+				"%s meta_back_getconn: candidates=%d conn=%s inserted\n",
+				op->o_log_prefix, ncandidates, buf );
+		}
+
+	} else {
+		if ( LogTest( LDAP_DEBUG_TRACE ) ) {
+			char buf[STRLENOF("4294967295U") + 1] = { 0 };
+			mi->mi_ldap_extra->connid2str( &mc->mc_base, buf, sizeof(buf) );
+
+			Debug( LDAP_DEBUG_TRACE,
+				"%s meta_back_getconn: candidates=%d conn=%s fetched\n",
+				op->o_log_prefix, ncandidates, buf );
+		}
+	}
+
+	return mc;
+}
+
+void
+meta_back_release_conn_lock(
+       	metainfo_t		*mi,
+	metaconn_t		*mc,
+	int			dolock )
+{
+	assert( mc != NULL );
+
+	if ( dolock ) {
+		ldap_pvt_thread_mutex_lock( &mi->mi_conninfo.lai_mutex );
+	}
+	assert( mc->mc_refcnt > 0 );
+	mc->mc_refcnt--;
+	/* NOTE: the connection is removed if either it is tainted
+	 * or if it is shared and no one else is using it.  This needs
+	 * to occur because for intrinsic reasons cached connections
+	 * that are not privileged would live forever and pollute
+	 * the connection space (and eat up resources).  Maybe this
+	 * should be configurable... */
+	if ( LDAP_BACK_CONN_TAINTED( mc ) || !LDAP_BACK_CONN_CACHED( mc ) ) {
+#if META_BACK_PRINT_CONNTREE > 0
+		meta_back_print_conntree( mi, ">>> meta_back_release_conn" );
+#endif /* META_BACK_PRINT_CONNTREE */
+
+		if ( LDAP_BACK_PCONN_ISPRIV( mc ) ) {
+			if ( mc->mc_q.tqe_prev != NULL ) {
+				assert( LDAP_BACK_CONN_CACHED( mc ) );
+				assert( mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num > 0 );
+				LDAP_TAILQ_REMOVE( &mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_priv, mc, mc_q );
+				mi->mi_conn_priv[ LDAP_BACK_CONN2PRIV( mc ) ].mic_num--;
+				LDAP_TAILQ_ENTRY_INIT( mc, mc_q );
+
+			} else {
+				assert( !LDAP_BACK_CONN_CACHED( mc ) );
+			}
+
+		} else if ( LDAP_BACK_CONN_CACHED( mc ) ) {
+			metaconn_t	*tmpmc;
+
+			tmpmc = ldap_tavl_delete( &mi->mi_conninfo.lai_tree,
+				( caddr_t )mc, meta_back_conndnmc_cmp );
+
+			/* Overparanoid, but useful... */
+			assert( tmpmc == NULL || tmpmc == mc );
+		}
+
+		LDAP_BACK_CONN_CACHED_CLEAR( mc );
+
+#if META_BACK_PRINT_CONNTREE > 0
+		meta_back_print_conntree( mi, "<<< meta_back_release_conn" );
+#endif /* META_BACK_PRINT_CONNTREE */
+
+		if ( mc->mc_refcnt == 0 ) {
+			meta_back_conn_free( mc );
+			mc = NULL;
+		}
+	}
+
+	if ( mc != NULL && LDAP_BACK_CONN_BINDING( mc ) ) {
+		LDAP_BACK_CONN_BINDING_CLEAR( mc );
+	}
+
+	if ( dolock ) {
+		ldap_pvt_thread_mutex_unlock( &mi->mi_conninfo.lai_mutex );
+	}
+}
+
+void
+meta_back_quarantine(
+	Operation	*op,
+	SlapReply	*rs,
+	int		candidate )
+{
+	metainfo_t		*mi = (metainfo_t *)op->o_bd->be_private;
+	metatarget_t		*mt = mi->mi_targets[ candidate ];
+
+	slap_retry_info_t	*ri = &mt->mt_quarantine;
+
+	ldap_pvt_thread_mutex_lock( &mt->mt_quarantine_mutex );
+
+	if ( rs->sr_err == LDAP_UNAVAILABLE ) {
+		time_t	new_last = slap_get_time();
+
+		switch ( mt->mt_isquarantined ) {
+		case LDAP_BACK_FQ_NO:
+			if ( ri->ri_last == new_last ) {
+				goto done;
+			}
+
+			Debug( LDAP_DEBUG_ANY,
+				"%s meta_back_quarantine[%d]: enter.\n",
+				op->o_log_prefix, candidate );
+
+			ri->ri_idx = 0;
+			ri->ri_count = 0;
+			break;
+
+		case LDAP_BACK_FQ_RETRYING:
+			Debug(LDAP_DEBUG_ANY,
+			      "%s meta_back_quarantine[%d]: block #%d try #%d failed.\n",
+			      op->o_log_prefix, candidate, ri->ri_idx,
+			      ri->ri_count );
+
+			++ri->ri_count;
+			if ( ri->ri_num[ ri->ri_idx ] != SLAP_RETRYNUM_FOREVER
+				&& ri->ri_count == ri->ri_num[ ri->ri_idx ] )
+			{
+				ri->ri_count = 0;
+				++ri->ri_idx;
+			}
+			break;
+
+		default:
+			goto done;
+		}
+
+		mt->mt_isquarantined = LDAP_BACK_FQ_YES;
+		ri->ri_last = new_last;
+
+	} else if ( mt->mt_isquarantined == LDAP_BACK_FQ_RETRYING ) {
+		Debug( LDAP_DEBUG_ANY,
+			"%s meta_back_quarantine[%d]: exit.\n",
+			op->o_log_prefix, candidate );
+
+		if ( mi->mi_quarantine_f ) {
+			(void)mi->mi_quarantine_f( mi, candidate,
+				mi->mi_quarantine_p );
+		}
+
+		ri->ri_count = 0;
+		ri->ri_idx = 0;
+		mt->mt_isquarantined = LDAP_BACK_FQ_NO;
+	}
+
+done:;
+	ldap_pvt_thread_mutex_unlock( &mt->mt_quarantine_mutex );
+}