Adding upstream version 2.4.57+dfsg.upstream/2.4.57+dfsgupstream

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

1 files changed, 1549 insertions, 0 deletions

diff --git a/servers/slapd/backglue.c b/servers/slapd/backglue.c
new file mode 100644
index 0000000..1c3354e
--- /dev/null
+++ b/servers/slapd/backglue.c
@@ -0,0 +1,1549 @@
+/* backglue.c - backend glue */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 2001-2021 The OpenLDAP Foundation.
+ * 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>.
+ */
+
+/*
+ * Functions to glue a bunch of other backends into a single tree.
+ * All of the glued backends must share a common suffix. E.g., you
+ * can glue o=foo and ou=bar,o=foo but you can't glue o=foo and o=bar.
+ *
+ * The purpose of these functions is to allow you to split a single database
+ * into pieces (for load balancing purposes, whatever) but still be able
+ * to treat it as a single database after it's been split. As such, each
+ * of the glued backends should have identical rootdn.
+ *  -- Howard Chu
+ */
+
+#include "portable.h"
+
+#include <stdio.h>
+
+#include <ac/string.h>
+#include <ac/socket.h>
+
+#define SLAPD_TOOLS
+#include "slap.h"
+#include "lutil.h"
+#include "config.h"
+
+typedef struct gluenode {
+	BackendDB *gn_be;
+	struct berval gn_pdn;
+} gluenode;
+
+typedef struct glueinfo {
+	int gi_nodes;
+	struct berval gi_pdn;
+	gluenode gi_n[1];
+} glueinfo;
+
+static slap_overinst	glue;
+
+static int glueMode;
+static BackendDB *glueBack;
+static BackendDB glueBackDone;
+#define GLUEBACK_DONE (&glueBackDone)
+
+static slap_overinst * glue_tool_inst( BackendInfo *bi);
+
+static slap_response glue_op_response;
+
+/* Just like select_backend, but only for our backends */
+static BackendDB *
+glue_back_select (
+	BackendDB *be,
+	struct berval *dn
+)
+{
+	slap_overinst	*on = (slap_overinst *)be->bd_info;
+	glueinfo		*gi = (glueinfo *)on->on_bi.bi_private;
+	int i;
+
+	for (i = gi->gi_nodes-1; i >= 0; i--) {
+		assert( gi->gi_n[i].gn_be->be_nsuffix != NULL );
+
+		if (dnIsSuffix(dn, &gi->gi_n[i].gn_be->be_nsuffix[0])) {
+			return gi->gi_n[i].gn_be;
+		}
+	}
+	be->bd_info = on->on_info->oi_orig;
+	return be;
+}
+
+
+typedef struct glue_state {
+	char *matched;
+	BerVarray refs;
+	LDAPControl **ctrls;
+	int err;
+	int matchlen;
+	int nrefs;
+	int nctrls;
+} glue_state;
+
+static int
+glue_op_cleanup( Operation *op, SlapReply *rs )
+{
+	/* This is not a final result */
+	if (rs->sr_type == REP_RESULT )
+		rs->sr_type = REP_GLUE_RESULT;
+	return SLAP_CB_CONTINUE;
+}
+
+static int
+glue_op_response ( Operation *op, SlapReply *rs )
+{
+	glue_state *gs = op->o_callback->sc_private;
+
+	switch(rs->sr_type) {
+	case REP_SEARCH:
+	case REP_SEARCHREF:
+	case REP_INTERMEDIATE:
+		return SLAP_CB_CONTINUE;
+
+	default:
+		if (rs->sr_err == LDAP_SUCCESS ||
+			rs->sr_err == LDAP_SIZELIMIT_EXCEEDED ||
+			rs->sr_err == LDAP_TIMELIMIT_EXCEEDED ||
+			rs->sr_err == LDAP_ADMINLIMIT_EXCEEDED ||
+			rs->sr_err == LDAP_NO_SUCH_OBJECT ||
+			gs->err != LDAP_SUCCESS)
+			gs->err = rs->sr_err;
+		if (gs->err == LDAP_SUCCESS && gs->matched) {
+			ch_free (gs->matched);
+			gs->matched = NULL;
+			gs->matchlen = 0;
+		}
+		if (gs->err != LDAP_SUCCESS && rs->sr_matched) {
+			int len;
+			len = strlen (rs->sr_matched);
+			if (len > gs->matchlen) {
+				if (gs->matched)
+					ch_free (gs->matched);
+				gs->matched = ch_strdup (rs->sr_matched);
+				gs->matchlen = len;
+			}
+		}
+		if (rs->sr_ref) {
+			int i, j, k;
+			BerVarray new;
+
+			for (i=0; rs->sr_ref[i].bv_val; i++);
+
+			j = gs->nrefs;
+			if (!j) {
+				new = ch_malloc ((i+1)*sizeof(struct berval));
+			} else {
+				new = ch_realloc(gs->refs,
+					(j+i+1)*sizeof(struct berval));
+			}
+			for (k=0; k<i; j++,k++) {
+				ber_dupbv( &new[j], &rs->sr_ref[k] );
+			}
+			new[j].bv_val = NULL;
+			gs->nrefs = j;
+			gs->refs = new;
+		}
+		if (rs->sr_ctrls) {
+			int i, j, k;
+			LDAPControl **newctrls;
+
+			for (i=0; rs->sr_ctrls[i]; i++);
+
+			j = gs->nctrls;
+			if (!j) {
+				newctrls = op->o_tmpalloc((i+1)*sizeof(LDAPControl *),
+					op->o_tmpmemctx);
+			} else {
+				/* Forget old pagedResults response if we're sending
+				 * a new one now
+				 */
+				if ( get_pagedresults( op ) > SLAP_CONTROL_IGNORED ) {
+					int newpage = 0;
+					for ( k=0; k<i; k++ ) {
+						if ( !strcmp(rs->sr_ctrls[k]->ldctl_oid,
+							LDAP_CONTROL_PAGEDRESULTS )) {
+							newpage = 1;
+							break;
+						}
+					}
+					if ( newpage ) {
+						for ( k=0; k<j; k++ ) {
+							if ( !strcmp(gs->ctrls[k]->ldctl_oid,
+								LDAP_CONTROL_PAGEDRESULTS ))
+							{
+								op->o_tmpfree(gs->ctrls[k], op->o_tmpmemctx);
+								gs->ctrls[k] = gs->ctrls[--j];
+								gs->ctrls[j] = NULL;
+								break;
+							}
+						}
+					}
+				}
+				newctrls = op->o_tmprealloc(gs->ctrls,
+					(j+i+1)*sizeof(LDAPControl *), op->o_tmpmemctx);
+			}
+			for (k=0; k<i; j++,k++) {
+				ber_len_t oidlen = strlen( rs->sr_ctrls[k]->ldctl_oid );
+				newctrls[j] = op->o_tmpalloc(sizeof(LDAPControl) + oidlen + 1 + rs->sr_ctrls[k]->ldctl_value.bv_len + 1,
+					op->o_tmpmemctx);
+				newctrls[j]->ldctl_iscritical = rs->sr_ctrls[k]->ldctl_iscritical;
+				newctrls[j]->ldctl_oid = (char *)&newctrls[j][1];
+				lutil_strcopy( newctrls[j]->ldctl_oid, rs->sr_ctrls[k]->ldctl_oid );
+				if ( !BER_BVISNULL( &rs->sr_ctrls[k]->ldctl_value ) ) {
+					newctrls[j]->ldctl_value.bv_val = &newctrls[j]->ldctl_oid[oidlen + 1];
+					newctrls[j]->ldctl_value.bv_len = rs->sr_ctrls[k]->ldctl_value.bv_len;
+					lutil_memcopy( newctrls[j]->ldctl_value.bv_val,
+						rs->sr_ctrls[k]->ldctl_value.bv_val,
+						rs->sr_ctrls[k]->ldctl_value.bv_len + 1 );
+				} else {
+					BER_BVZERO( &newctrls[j]->ldctl_value );
+				}
+			}
+			newctrls[j] = NULL;
+			gs->nctrls = j;
+			gs->ctrls = newctrls;
+		}
+	}
+	return 0;
+}
+
+static int
+glue_op_func ( Operation *op, SlapReply *rs )
+{
+	slap_overinst	*on = (slap_overinst *)op->o_bd->bd_info;
+	BackendDB *b0 = op->o_bd;
+	BackendInfo *bi0 = op->o_bd->bd_info;
+	BI_op_modify **func;
+	slap_operation_t which = op_bind;
+	int rc;
+
+	op->o_bd = glue_back_select (b0, &op->o_req_ndn);
+
+	/* If we're on the primary backend, let overlay framework handle it */
+	if ( op->o_bd == b0 )
+		return SLAP_CB_CONTINUE;
+
+	b0->bd_info = on->on_info->oi_orig;
+
+	switch(op->o_tag) {
+	case LDAP_REQ_ADD: which = op_add; break;
+	case LDAP_REQ_DELETE: which = op_delete; break;
+	case LDAP_REQ_MODIFY: which = op_modify; break;
+	case LDAP_REQ_MODRDN: which = op_modrdn; break;
+	case LDAP_REQ_EXTENDED: which = op_extended; break;
+	default: assert( 0 ); break;
+	}
+
+	func = &op->o_bd->bd_info->bi_op_bind;
+	if ( func[which] )
+		rc = func[which]( op, rs );
+	else
+		rc = SLAP_CB_BYPASS;
+
+	op->o_bd = b0;
+	op->o_bd->bd_info = bi0;
+	return rc;
+}
+
+static int
+glue_op_abandon( Operation *op, SlapReply *rs )
+{
+	slap_overinst	*on = (slap_overinst *)op->o_bd->bd_info;
+	glueinfo		*gi = (glueinfo *)on->on_bi.bi_private;
+	BackendDB *b0 = op->o_bd;
+	BackendInfo *bi0 = op->o_bd->bd_info;
+	int i;
+
+	b0->bd_info = on->on_info->oi_orig;
+
+	for (i = gi->gi_nodes-1; i >= 0; i--) {
+		assert( gi->gi_n[i].gn_be->be_nsuffix != NULL );
+		op->o_bd = gi->gi_n[i].gn_be;
+		if ( op->o_bd == b0 )
+			continue;
+		if ( op->o_bd->bd_info->bi_op_abandon )
+			op->o_bd->bd_info->bi_op_abandon( op, rs );
+	}
+	op->o_bd = b0;
+	op->o_bd->bd_info = bi0;
+	return SLAP_CB_CONTINUE;
+}
+
+static int
+glue_response ( Operation *op, SlapReply *rs )
+{
+	BackendDB *be = op->o_bd;
+	be = glue_back_select (op->o_bd, &op->o_req_ndn);
+
+	/* If we're on the primary backend, let overlay framework handle it.
+	 * Otherwise, bail out.
+	 */
+	return ( op->o_bd == be ) ? SLAP_CB_CONTINUE : SLAP_CB_BYPASS;
+}
+
+static int
+glue_chk_referrals ( Operation *op, SlapReply *rs )
+{
+	slap_overinst	*on = (slap_overinst *)op->o_bd->bd_info;
+	BackendDB *b0 = op->o_bd;
+	BackendInfo *bi0 = op->o_bd->bd_info;
+	int rc;
+
+	op->o_bd = glue_back_select (b0, &op->o_req_ndn);
+	if ( op->o_bd == b0 )
+		return SLAP_CB_CONTINUE;
+
+	b0->bd_info = on->on_info->oi_orig;
+
+	if ( op->o_bd->bd_info->bi_chk_referrals )
+		rc = ( *op->o_bd->bd_info->bi_chk_referrals )( op, rs );
+	else
+		rc = SLAP_CB_CONTINUE;
+
+	op->o_bd = b0;
+	op->o_bd->bd_info = bi0;
+	return rc;
+}
+
+static int
+glue_chk_controls ( Operation *op, SlapReply *rs )
+{
+	slap_overinst	*on = (slap_overinst *)op->o_bd->bd_info;
+	BackendDB *b0 = op->o_bd;
+	BackendInfo *bi0 = op->o_bd->bd_info;
+	int rc = SLAP_CB_CONTINUE;
+
+	op->o_bd = glue_back_select (b0, &op->o_req_ndn);
+	if ( op->o_bd == b0 )
+		return SLAP_CB_CONTINUE;
+
+	b0->bd_info = on->on_info->oi_orig;
+
+	/* if the subordinate database has overlays, the bi_chk_controls()
+	 * hook is actually over_aux_chk_controls(); in case it actually
+	 * wraps a missing hok, we need to mimic the behavior
+	 * of the frontend applied to that database */
+	if ( op->o_bd->bd_info->bi_chk_controls ) {
+		rc = ( *op->o_bd->bd_info->bi_chk_controls )( op, rs );
+	}
+
+	
+	if ( rc == SLAP_CB_CONTINUE ) {
+		rc = backend_check_controls( op, rs );
+	}
+
+	op->o_bd = b0;
+	op->o_bd->bd_info = bi0;
+	return rc;
+}
+
+/* ITS#4615 - overlays configured above the glue overlay should be
+ * invoked for the entire glued tree. Overlays configured below the
+ * glue overlay should only be invoked on the primary backend.
+ * So, if we're searching on any subordinates, we need to force the
+ * current overlay chain to stop processing, without stopping the
+ * overall callback flow.
+ */
+static int
+glue_sub_search( Operation *op, SlapReply *rs, BackendDB *b0,
+	slap_overinst *on )
+{
+	/* Process any overlays on the primary backend */
+	if ( op->o_bd == b0 && on->on_next ) {
+		BackendInfo *bi = op->o_bd->bd_info;
+		int rc = SLAP_CB_CONTINUE;
+		for ( on=on->on_next; on; on=on->on_next ) {
+			op->o_bd->bd_info = (BackendInfo *)on;
+			if ( on->on_bi.bi_op_search ) {
+				rc = on->on_bi.bi_op_search( op, rs );
+				if ( rc != SLAP_CB_CONTINUE )
+					break;
+			}
+		}
+		op->o_bd->bd_info = bi;
+		if ( rc != SLAP_CB_CONTINUE )
+			return rc;
+	}
+	return op->o_bd->be_search( op, rs );
+}
+
+static const ID glueID = NOID;
+static const struct berval gluecookie = { sizeof( glueID ), (char *)&glueID };
+
+static int
+glue_op_search ( Operation *op, SlapReply *rs )
+{
+	slap_overinst	*on = (slap_overinst *)op->o_bd->bd_info;
+	glueinfo		*gi = (glueinfo *)on->on_bi.bi_private;
+	BackendDB *b0 = op->o_bd;
+	BackendDB *b1 = NULL, *btmp;
+	BackendInfo *bi0 = op->o_bd->bd_info;
+	int i;
+	long stoptime = 0, starttime;
+	glue_state gs = {NULL, NULL, NULL, 0, 0, 0, 0};
+	slap_callback cb = { NULL, glue_op_response, glue_op_cleanup, NULL };
+	int scope0, tlimit0;
+	struct berval dn, ndn, *pdn;
+
+	cb.sc_private = &gs;
+
+	cb.sc_next = op->o_callback;
+
+	starttime = op->o_time;
+	stoptime = slap_get_time () + op->ors_tlimit;
+
+	/* reset dummy cookie used to keep paged results going across databases */
+	if ( get_pagedresults( op ) > SLAP_CONTROL_IGNORED
+		&& bvmatch( &((PagedResultsState *)op->o_pagedresults_state)->ps_cookieval, &gluecookie ) )
+	{
+		PagedResultsState *ps = op->o_pagedresults_state;
+		BerElementBuffer berbuf;
+		BerElement *ber = (BerElement *)&berbuf;
+		struct berval cookie = BER_BVC(""), value;
+		int c;
+
+		for (c = 0; op->o_ctrls[c] != NULL; c++) {
+			if (strcmp(op->o_ctrls[c]->ldctl_oid, LDAP_CONTROL_PAGEDRESULTS) == 0)
+				break;
+		}
+
+		assert( op->o_ctrls[c] != NULL );
+
+		ber_init2( ber, NULL, LBER_USE_DER );
+		ber_printf( ber, "{iO}", ps->ps_size, &cookie );
+		ber_flatten2( ber, &value, 0 );
+		assert( op->o_ctrls[c]->ldctl_value.bv_len >= value.bv_len );
+		op->o_ctrls[c]->ldctl_value.bv_len = value.bv_len;
+		lutil_memcopy( op->o_ctrls[c]->ldctl_value.bv_val,
+			value.bv_val, value.bv_len );
+		ber_free_buf( ber );
+
+		ps->ps_cookie = (PagedResultsCookie)0;
+		BER_BVZERO( &ps->ps_cookieval );
+	}
+
+	op->o_bd = glue_back_select (b0, &op->o_req_ndn);
+	b0->bd_info = on->on_info->oi_orig;
+
+	switch (op->ors_scope) {
+	case LDAP_SCOPE_BASE:
+		if ( op->o_bd == b0 )
+			return SLAP_CB_CONTINUE;
+
+		if (op->o_bd && op->o_bd->be_search) {
+			rs->sr_err = op->o_bd->be_search( op, rs );
+		} else {
+			rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
+		}
+		return rs->sr_err;
+
+	case LDAP_SCOPE_ONELEVEL:
+	case LDAP_SCOPE_SUBTREE:
+	case LDAP_SCOPE_SUBORDINATE: /* FIXME */
+		op->o_callback = &cb;
+		rs->sr_err = gs.err = LDAP_UNWILLING_TO_PERFORM;
+		scope0 = op->ors_scope;
+		tlimit0 = op->ors_tlimit;
+		dn = op->o_req_dn;
+		ndn = op->o_req_ndn;
+		b1 = op->o_bd;
+
+		/*
+		 * Execute in reverse order, most specific first 
+		 */
+		for (i = gi->gi_nodes; i >= 0; i--) {
+			if ( i == gi->gi_nodes ) {
+				btmp = b0;
+				pdn = &gi->gi_pdn;
+			} else {
+				btmp = gi->gi_n[i].gn_be;
+				pdn = &gi->gi_n[i].gn_pdn;
+			}
+			if (!btmp || !btmp->be_search)
+				continue;
+			if (!dnIsSuffix(&btmp->be_nsuffix[0], &b1->be_nsuffix[0]))
+				continue;
+			if (get_no_subordinate_glue(op) && btmp != b1)
+				continue;
+			/* If we remembered which backend we were on before,
+			 * skip down to it now
+			 */
+			if ( get_pagedresults( op ) > SLAP_CONTROL_IGNORED &&
+				op->o_conn->c_pagedresults_state.ps_be &&
+				op->o_conn->c_pagedresults_state.ps_be != btmp )
+				continue;
+
+			if (tlimit0 != SLAP_NO_LIMIT) {
+				op->o_time = slap_get_time();
+				op->ors_tlimit = stoptime - op->o_time;
+				if (op->ors_tlimit <= 0) {
+					rs->sr_err = gs.err = LDAP_TIMELIMIT_EXCEEDED;
+					break;
+				}
+			}
+			rs->sr_err = 0;
+			/*
+			 * check for abandon 
+			 */
+			if (op->o_abandon) {
+				goto end_of_loop;
+			}
+			op->o_bd = btmp;
+
+			assert( op->o_bd->be_suffix != NULL );
+			assert( op->o_bd->be_nsuffix != NULL );
+			
+			if (scope0 == LDAP_SCOPE_ONELEVEL && 
+				dn_match(pdn, &ndn))
+			{
+				struct berval mdn, mndn;
+				op->ors_scope = LDAP_SCOPE_BASE;
+				mdn = op->o_req_dn = op->o_bd->be_suffix[0];
+				mndn = op->o_req_ndn = op->o_bd->be_nsuffix[0];
+				rs->sr_err = op->o_bd->be_search(op, rs);
+				if ( rs->sr_err == LDAP_NO_SUCH_OBJECT ) {
+					gs.err = LDAP_SUCCESS;
+				}
+				op->ors_scope = LDAP_SCOPE_ONELEVEL;
+				if ( op->o_req_dn.bv_val == mdn.bv_val )
+					op->o_req_dn = dn;
+				if ( op->o_req_ndn.bv_val == mndn.bv_val )
+					op->o_req_ndn = ndn;
+
+			} else if (scope0 == LDAP_SCOPE_SUBTREE &&
+				dn_match(&op->o_bd->be_nsuffix[0], &ndn))
+			{
+				rs->sr_err = glue_sub_search( op, rs, b0, on );
+
+			} else if (scope0 == LDAP_SCOPE_SUBTREE &&
+				dnIsSuffix(&op->o_bd->be_nsuffix[0], &ndn))
+			{
+				struct berval mdn, mndn;
+				mdn = op->o_req_dn = op->o_bd->be_suffix[0];
+				mndn = op->o_req_ndn = op->o_bd->be_nsuffix[0];
+				rs->sr_err = glue_sub_search( op, rs, b0, on );
+				if ( rs->sr_err == LDAP_NO_SUCH_OBJECT ) {
+					gs.err = LDAP_SUCCESS;
+				}
+				if ( op->o_req_dn.bv_val == mdn.bv_val )
+					op->o_req_dn = dn;
+				if ( op->o_req_ndn.bv_val == mndn.bv_val )
+					op->o_req_ndn = ndn;
+
+			} else if (dnIsSuffix(&ndn, &op->o_bd->be_nsuffix[0])) {
+				rs->sr_err = glue_sub_search( op, rs, b0, on );
+			}
+
+			switch ( gs.err ) {
+
+			/*
+			 * Add errors that should result in dropping
+			 * the search
+			 */
+			case LDAP_SIZELIMIT_EXCEEDED:
+			case LDAP_TIMELIMIT_EXCEEDED:
+			case LDAP_ADMINLIMIT_EXCEEDED:
+			case LDAP_NO_SUCH_OBJECT:
+#ifdef LDAP_CONTROL_X_CHAINING_BEHAVIOR
+			case LDAP_X_CANNOT_CHAIN:
+#endif /* LDAP_CONTROL_X_CHAINING_BEHAVIOR */
+				goto end_of_loop;
+
+			case LDAP_SUCCESS:
+				if ( get_pagedresults( op ) > SLAP_CONTROL_IGNORED ) {
+					PagedResultsState *ps = op->o_pagedresults_state;
+
+					/* Assume this backend can be forgotten now */
+					op->o_conn->c_pagedresults_state.ps_be = NULL;
+
+					/* If we have a full page, exit the loop. We may
+					 * need to remember this backend so we can continue
+					 * from here on a subsequent request.
+					 */
+					if ( rs->sr_nentries >= ps->ps_size ) {
+						PagedResultsState *cps = &op->o_conn->c_pagedresults_state;
+						
+						/* Don't bother to remember the first backend.
+						 * Only remember the last one if there's more state left.
+						 */
+						if ( op->o_bd != b0 &&
+							( cps->ps_cookie != NOID
+								|| !BER_BVISNULL( &cps->ps_cookieval )
+								|| op->o_bd != gi->gi_n[0].gn_be ) )
+						{
+							op->o_conn->c_pagedresults_state.ps_be = op->o_bd;
+						}
+
+						/* Check whether the cookie is empty,
+						 * and give remaining databases a chance
+						 */
+						if ( op->o_bd != gi->gi_n[0].gn_be || cps->ps_cookie == NOID ) {
+							int		c;
+
+							for ( c = 0; gs.ctrls[c] != NULL; c++ ) {
+								if ( strcmp( gs.ctrls[c]->ldctl_oid, LDAP_CONTROL_PAGEDRESULTS ) == 0 ) {
+									break;
+								}
+							}
+
+							if ( gs.ctrls[c] != NULL ) {
+								BerElementBuffer berbuf;
+								BerElement	*ber = (BerElement *)&berbuf;
+								ber_tag_t	tag;
+								ber_int_t	size;
+								struct berval	cookie, value;
+							
+								ber_init2( ber, &gs.ctrls[c]->ldctl_value, LBER_USE_DER );
+
+								tag = ber_scanf( ber, "{im}", &size, &cookie );
+								assert( tag != LBER_ERROR );
+
+								if ( BER_BVISEMPTY( &cookie ) && op->o_bd != gi->gi_n[0].gn_be ) {
+									/* delete old, create new cookie with NOID */
+									PagedResultsCookie respcookie = (PagedResultsCookie)NOID;
+									ber_len_t oidlen = strlen( gs.ctrls[c]->ldctl_oid );
+									LDAPControl *newctrl;
+
+									/* it's next database's turn */
+									if ( btmp == b0 ) {
+										op->o_conn->c_pagedresults_state.ps_be = gi->gi_n[gi->gi_nodes - 1].gn_be;
+
+									} else {
+										op->o_conn->c_pagedresults_state.ps_be = gi->gi_n[(i > 0 ? i - 1: 0)].gn_be;
+									}
+
+									cookie.bv_val = (char *)&respcookie;
+									cookie.bv_len = sizeof( PagedResultsCookie );
+
+									ber_init2( ber, NULL, LBER_USE_DER );
+									ber_printf( ber, "{iO}", 0, &cookie );
+									ber_flatten2( ber, &value, 0 );
+
+									newctrl = op->o_tmprealloc( gs.ctrls[c],
+										sizeof(LDAPControl) + oidlen + 1 + value.bv_len + 1,
+										op->o_tmpmemctx);
+									newctrl->ldctl_iscritical = gs.ctrls[c]->ldctl_iscritical;
+									newctrl->ldctl_oid = (char *)&newctrl[1];
+									lutil_strcopy( newctrl->ldctl_oid, gs.ctrls[c]->ldctl_oid );
+									newctrl->ldctl_value.bv_len = value.bv_len;
+									lutil_memcopy( newctrl->ldctl_value.bv_val,
+										value.bv_val, value.bv_len );
+
+									gs.ctrls[c] = newctrl;
+
+									ber_free_buf( ber );
+
+								} else if ( !BER_BVISEMPTY( &cookie ) && op->o_bd != b0 ) {
+									/* if cookie not empty, it's again this database's turn */
+									op->o_conn->c_pagedresults_state.ps_be = op->o_bd;
+								}
+							}
+						}
+
+						goto end_of_loop;
+					}
+
+					/* This backend has run out of entries, but more responses
+					 * can fit in the page. Fake a reset of the state so the
+					 * next backend will start up properly. Only back-[bh]db
+					 * and back-sql look at this state info.
+					 */
+					ps->ps_cookie = (PagedResultsCookie)0;
+					BER_BVZERO( &ps->ps_cookieval );
+
+					{
+						/* change the size of the page in the request
+						 * that will be propagated, and reset the cookie */
+						BerElementBuffer berbuf;
+						BerElement *ber = (BerElement *)&berbuf;
+						int size = ps->ps_size - rs->sr_nentries;
+						struct berval cookie = BER_BVC(""), value;
+						int c;
+
+						for (c = 0; op->o_ctrls[c] != NULL; c++) {
+							if (strcmp(op->o_ctrls[c]->ldctl_oid, LDAP_CONTROL_PAGEDRESULTS) == 0)
+								break;
+						}
+
+						assert( op->o_ctrls[c] != NULL );
+
+						ber_init2( ber, NULL, LBER_USE_DER );
+						ber_printf( ber, "{iO}", size, &cookie );
+						ber_flatten2( ber, &value, 0 );
+						assert( op->o_ctrls[c]->ldctl_value.bv_len >= value.bv_len );
+						op->o_ctrls[c]->ldctl_value.bv_len = value.bv_len;
+						lutil_memcopy( op->o_ctrls[c]->ldctl_value.bv_val,
+							value.bv_val, value.bv_len );
+						ber_free_buf( ber );
+					}
+				}
+				
+			default:
+				break;
+			}
+		}
+end_of_loop:;
+		op->ors_scope = scope0;
+		op->ors_tlimit = tlimit0;
+		op->o_time = starttime;
+
+		break;
+	}
+
+	op->o_callback = cb.sc_next;
+	if ( op->o_abandon ) {
+		rs->sr_err = SLAPD_ABANDON;
+	} else {
+		rs->sr_err = gs.err;
+		rs->sr_matched = gs.matched;
+		rs->sr_ref = gs.refs;
+	}
+	rs->sr_ctrls = gs.ctrls;
+
+	send_ldap_result( op, rs );
+
+	op->o_bd = b0;
+	op->o_bd->bd_info = bi0;
+	if (gs.matched)
+		free (gs.matched);
+	if (gs.refs)
+		ber_bvarray_free(gs.refs);
+	if (gs.ctrls) {
+		for (i = gs.nctrls; --i >= 0; ) {
+			op->o_tmpfree(gs.ctrls[i], op->o_tmpmemctx);
+		}
+		op->o_tmpfree(gs.ctrls, op->o_tmpmemctx);
+	}
+	return rs->sr_err;
+}
+
+static BackendDB toolDB;
+
+static int
+glue_tool_entry_open (
+	BackendDB *b0,
+	int mode
+)
+{
+	slap_overinfo	*oi = (slap_overinfo *)b0->bd_info;
+
+	/* We don't know which backend to talk to yet, so just
+	 * remember the mode and move on...
+	 */
+
+	glueMode = mode;
+	glueBack = NULL;
+	toolDB = *b0;
+	toolDB.bd_info = oi->oi_orig;
+
+	/* Sanity checks */
+	{
+		slap_overinst *on = glue_tool_inst( b0->bd_info );
+		glueinfo	*gi = on->on_bi.bi_private;
+
+		int i;
+		for (i = 0; i < gi->gi_nodes; i++) {
+			BackendDB *bd;
+			struct berval pdn;
+	
+			dnParent( &gi->gi_n[i].gn_be->be_nsuffix[0], &pdn );
+			bd = select_backend( &pdn, 0 );
+			if ( bd ) {
+				ID id;
+				BackendDB db;
+	
+				if ( overlay_is_over( bd ) ) {
+					slap_overinfo *oi = (slap_overinfo *)bd->bd_info;
+					db = *bd;
+					db.bd_info = oi->oi_orig;
+					bd = &db;
+				}
+	
+				if ( !bd->bd_info->bi_tool_dn2id_get
+					|| !bd->bd_info->bi_tool_entry_open
+					|| !bd->bd_info->bi_tool_entry_close )
+				{
+					continue;
+				}
+	
+				bd->bd_info->bi_tool_entry_open( bd, 0 );
+				id = bd->bd_info->bi_tool_dn2id_get( bd, &gi->gi_n[i].gn_be->be_nsuffix[0] );
+				bd->bd_info->bi_tool_entry_close( bd );
+				if ( id != NOID ) {
+					Debug( LDAP_DEBUG_ANY,
+						"glue_tool_entry_open: subordinate database suffix entry DN=\"%s\" also present in superior database rooted at DN=\"%s\"\n",
+						gi->gi_n[i].gn_be->be_suffix[0].bv_val, bd->be_suffix[0].bv_val, 0 );
+					return LDAP_OTHER;
+				}
+			}
+		}
+	}
+	
+	return 0;
+}
+
+static int
+glue_tool_entry_close (
+	BackendDB *b0
+)
+{
+	int rc = 0;
+
+	if (glueBack && glueBack != GLUEBACK_DONE) {
+		if (!glueBack->be_entry_close)
+			return 0;
+		rc = glueBack->be_entry_close (glueBack);
+	}
+	return rc;
+}
+
+static slap_overinst *
+glue_tool_inst(
+	BackendInfo *bi
+)
+{
+	slap_overinfo	*oi = (slap_overinfo *)bi;
+	slap_overinst	*on;
+
+	for ( on = oi->oi_list; on; on=on->on_next ) {
+		if ( !strcmp( on->on_bi.bi_type, glue.on_bi.bi_type ))
+			return on;
+	}
+	return NULL;
+}
+
+/* This function will only be called in tool mode */
+static int
+glue_open (
+	BackendInfo *bi
+)
+{
+	slap_overinst *on = glue_tool_inst( bi );
+	glueinfo		*gi = on->on_bi.bi_private;
+	static int glueOpened = 0;
+	int i, j, same, bsame = 0, rc = 0;
+	ConfigReply cr = {0};
+
+	if (glueOpened) return 0;
+
+	glueOpened = 1;
+
+	/* If we were invoked in tool mode, open all the underlying backends */
+	if (slapMode & SLAP_TOOL_MODE) {
+		for (i = 0; i<gi->gi_nodes; i++) {
+			same = 0;
+			/* Same bi_open as our main backend? */
+			if ( gi->gi_n[i].gn_be->bd_info->bi_open ==
+				on->on_info->oi_orig->bi_open )
+				bsame = 1;
+
+			/* Loop thru the bd_info's and make sure we only
+			 * invoke their bi_open functions once each.
+			 */
+			for ( j = 0; j<i; j++ ) {
+				if ( gi->gi_n[i].gn_be->bd_info->bi_open ==
+					gi->gi_n[j].gn_be->bd_info->bi_open ) {
+					same = 1;
+					break;
+				}
+			}
+			/* OK, it's unique and non-NULL, call it. */
+			if ( !same && gi->gi_n[i].gn_be->bd_info->bi_open )
+				rc = gi->gi_n[i].gn_be->bd_info->bi_open(
+					gi->gi_n[i].gn_be->bd_info );
+			/* Let backend.c take care of the rest of startup */
+			if ( !rc )
+				rc = backend_startup_one( gi->gi_n[i].gn_be, &cr );
+			if ( rc ) break;
+		}
+		if ( !rc && !bsame && on->on_info->oi_orig->bi_open )
+			rc = on->on_info->oi_orig->bi_open( on->on_info->oi_orig );
+
+	} /* other case is impossible */
+	return rc;
+}
+
+/* This function will only be called in tool mode */
+static int
+glue_close (
+	BackendInfo *bi
+)
+{
+	static int glueClosed = 0;
+	int rc = 0;
+
+	if (glueClosed) return 0;
+
+	glueClosed = 1;
+
+	if (slapMode & SLAP_TOOL_MODE) {
+		rc = backend_shutdown( NULL );
+	}
+	return rc;
+}
+
+static int
+glue_entry_get_rw (
+	Operation		*op,
+	struct berval	*dn,
+	ObjectClass		*oc,
+	AttributeDescription	*ad,
+	int	rw,
+	Entry	**e )
+{
+	int rc;
+	BackendDB *b0 = op->o_bd;
+	op->o_bd = glue_back_select( b0, dn );
+
+	if ( op->o_bd->be_fetch ) {
+		rc = op->o_bd->be_fetch( op, dn, oc, ad, rw, e );
+	} else {
+		rc = LDAP_UNWILLING_TO_PERFORM;
+	}
+	op->o_bd =b0;
+	return rc;
+}
+
+static int
+glue_entry_release_rw (
+	Operation *op,
+	Entry *e,
+	int rw
+)
+{
+	BackendDB *b0 = op->o_bd;
+	int rc = -1;
+
+	op->o_bd = glue_back_select (b0, &e->e_nname);
+
+	if ( op->o_bd->be_release ) {
+		rc = op->o_bd->be_release( op, e, rw );
+
+	} else {
+		/* FIXME: mimic be_entry_release_rw
+		 * when no be_release() available */
+		/* free entry */
+		entry_free( e );
+		rc = 0;
+	}
+	op->o_bd = b0;
+	return rc;
+}
+
+static struct berval *glue_base;
+static int glue_scope;
+static Filter *glue_filter;
+
+static ID
+glue_tool_entry_first (
+	BackendDB *b0
+)
+{
+	slap_overinst	*on = glue_tool_inst( b0->bd_info );
+	glueinfo		*gi = on->on_bi.bi_private;
+	int i;
+	ID rc;
+
+	/* If we're starting from scratch, start at the most general */
+	if (!glueBack) {
+		if ( toolDB.be_entry_open && toolDB.be_entry_first ) {
+			glueBack = &toolDB;
+		} else {
+			for (i = gi->gi_nodes-1; i >= 0; i--) {
+				if (gi->gi_n[i].gn_be->be_entry_open &&
+					gi->gi_n[i].gn_be->be_entry_first) {
+						glueBack = gi->gi_n[i].gn_be;
+					break;
+				}
+			}
+		}
+	}
+	if (!glueBack || !glueBack->be_entry_open || !glueBack->be_entry_first ||
+		glueBack->be_entry_open (glueBack, glueMode) != 0)
+		return NOID;
+
+	rc = glueBack->be_entry_first (glueBack);
+	while ( rc == NOID ) {
+		if ( glueBack && glueBack->be_entry_close )
+			glueBack->be_entry_close (glueBack);
+		for (i=0; i<gi->gi_nodes; i++) {
+			if (gi->gi_n[i].gn_be == glueBack)
+				break;
+		}
+		if (i == 0) {
+			glueBack = GLUEBACK_DONE;
+			break;
+		} else {
+			glueBack = gi->gi_n[i-1].gn_be;
+			rc = glue_tool_entry_first (b0);
+			if ( glueBack == GLUEBACK_DONE ) {
+				break;
+			}
+		}
+	}
+	return rc;
+}
+
+static ID
+glue_tool_entry_first_x (
+	BackendDB *b0,
+	struct berval *base,
+	int scope,
+	Filter *f
+)
+{
+	slap_overinst	*on = glue_tool_inst( b0->bd_info );
+	glueinfo		*gi = on->on_bi.bi_private;
+	int i;
+	ID rc;
+
+	glue_base = base;
+	glue_scope = scope;
+	glue_filter = f;
+
+	/* If we're starting from scratch, start at the most general */
+	if (!glueBack) {
+		if ( toolDB.be_entry_open && toolDB.be_entry_first_x ) {
+			glueBack = &toolDB;
+		} else {
+			for (i = gi->gi_nodes-1; i >= 0; i--) {
+				if (gi->gi_n[i].gn_be->be_entry_open &&
+					gi->gi_n[i].gn_be->be_entry_first_x)
+				{
+					glueBack = gi->gi_n[i].gn_be;
+					break;
+				}
+			}
+		}
+	}
+	if (!glueBack || !glueBack->be_entry_open || !glueBack->be_entry_first_x ||
+		glueBack->be_entry_open (glueBack, glueMode) != 0)
+		return NOID;
+
+	rc = glueBack->be_entry_first_x (glueBack,
+		glue_base, glue_scope, glue_filter);
+	while ( rc == NOID ) {
+		if ( glueBack && glueBack->be_entry_close )
+			glueBack->be_entry_close (glueBack);
+		for (i=0; i<gi->gi_nodes; i++) {
+			if (gi->gi_n[i].gn_be == glueBack)
+				break;
+		}
+		if (i == 0) {
+			glueBack = GLUEBACK_DONE;
+			break;
+		} else {
+			glueBack = gi->gi_n[i-1].gn_be;
+			rc = glue_tool_entry_first_x (b0,
+				glue_base, glue_scope, glue_filter);
+			if ( glueBack == GLUEBACK_DONE ) {
+				break;
+			}
+		}
+	}
+	return rc;
+}
+
+static ID
+glue_tool_entry_next (
+	BackendDB *b0
+)
+{
+	slap_overinst	*on = glue_tool_inst( b0->bd_info );
+	glueinfo		*gi = on->on_bi.bi_private;
+	int i;
+	ID rc;
+
+	if (!glueBack || !glueBack->be_entry_next)
+		return NOID;
+
+	rc = glueBack->be_entry_next (glueBack);
+
+	/* If we ran out of entries in one database, move on to the next */
+	while (rc == NOID) {
+		if ( glueBack && glueBack->be_entry_close )
+			glueBack->be_entry_close (glueBack);
+		for (i=0; i<gi->gi_nodes; i++) {
+			if (gi->gi_n[i].gn_be == glueBack)
+				break;
+		}
+		if (i == 0) {
+			glueBack = GLUEBACK_DONE;
+			break;
+		} else {
+			glueBack = gi->gi_n[i-1].gn_be;
+			if ( glue_base || glue_filter ) {
+				/* using entry_first_x() */
+				rc = glue_tool_entry_first_x (b0,
+					glue_base, glue_scope, glue_filter);
+
+			} else {
+				/* using entry_first() */
+				rc = glue_tool_entry_first (b0);
+			}
+			if ( glueBack == GLUEBACK_DONE ) {
+				break;
+			}
+		}
+	}
+	return rc;
+}
+
+static ID
+glue_tool_dn2id_get (
+	BackendDB *b0,
+	struct berval *dn
+)
+{
+	BackendDB *be, b2;
+	int rc = -1;
+
+	b2 = *b0;
+	b2.bd_info = (BackendInfo *)glue_tool_inst( b0->bd_info );
+	be = glue_back_select (&b2, dn);
+	if ( be == &b2 ) be = &toolDB;
+
+	if (!be->be_dn2id_get)
+		return NOID;
+
+	if (!glueBack) {
+		if ( be->be_entry_open ) {
+			rc = be->be_entry_open (be, glueMode);
+		}
+		if (rc != 0) {
+			return NOID;
+		}
+	} else if (be != glueBack) {
+		/* If this entry belongs in a different branch than the
+		 * previous one, close the current database and open the
+		 * new one.
+		 */
+		if ( glueBack->be_entry_close ) {
+			glueBack->be_entry_close (glueBack);
+		}
+		if ( be->be_entry_open ) {
+			rc = be->be_entry_open (be, glueMode);
+		}
+		if (rc != 0) {
+			return NOID;
+		}
+	}
+	glueBack = be;
+	return be->be_dn2id_get (be, dn);
+}
+
+static Entry *
+glue_tool_entry_get (
+	BackendDB *b0,
+	ID id
+)
+{
+	if (!glueBack || !glueBack->be_entry_get)
+		return NULL;
+
+	return glueBack->be_entry_get (glueBack, id);
+}
+
+static ID
+glue_tool_entry_put (
+	BackendDB *b0,
+	Entry *e,
+	struct berval *text
+)
+{
+	BackendDB *be, b2;
+	int rc = -1;
+
+	b2 = *b0;
+	b2.bd_info = (BackendInfo *)glue_tool_inst( b0->bd_info );
+	be = glue_back_select (&b2, &e->e_nname);
+	if ( be == &b2 ) be = &toolDB;
+
+	if (!be->be_entry_put)
+		return NOID;
+
+	if (!glueBack) {
+		if ( be->be_entry_open ) {
+			rc = be->be_entry_open (be, glueMode);
+		}
+		if (rc != 0) {
+			return NOID;
+		}
+	} else if (be != glueBack) {
+		/* If this entry belongs in a different branch than the
+		 * previous one, close the current database and open the
+		 * new one.
+		 */
+		if ( glueBack->be_entry_close ) {
+			glueBack->be_entry_close (glueBack);
+		}
+		if ( be->be_entry_open ) {
+			rc = be->be_entry_open (be, glueMode);
+		}
+		if (rc != 0) {
+			return NOID;
+		}
+	}
+	glueBack = be;
+	return be->be_entry_put (be, e, text);
+}
+
+static ID
+glue_tool_entry_modify (
+	BackendDB *b0,
+	Entry *e,
+	struct berval *text
+)
+{
+	if (!glueBack || !glueBack->be_entry_modify)
+		return NOID;
+
+	return glueBack->be_entry_modify (glueBack, e, text);
+}
+
+static int
+glue_tool_entry_reindex (
+	BackendDB *b0,
+	ID id,
+	AttributeDescription **adv
+)
+{
+	if (!glueBack || !glueBack->be_entry_reindex)
+		return -1;
+
+	return glueBack->be_entry_reindex (glueBack, id, adv);
+}
+
+static int
+glue_tool_sync (
+	BackendDB *b0
+)
+{
+	slap_overinst	*on = glue_tool_inst( b0->bd_info );
+	glueinfo		*gi = on->on_bi.bi_private;
+	BackendInfo		*bi = b0->bd_info;
+	int i;
+
+	/* just sync everyone */
+	for (i = 0; i<gi->gi_nodes; i++)
+		if (gi->gi_n[i].gn_be->be_sync)
+			gi->gi_n[i].gn_be->be_sync (gi->gi_n[i].gn_be);
+	b0->bd_info = on->on_info->oi_orig;
+	if ( b0->be_sync )
+		b0->be_sync( b0 );
+	b0->bd_info = bi;
+	return 0;
+}
+
+typedef struct glue_Addrec {
+	struct glue_Addrec *ga_next;
+	BackendDB *ga_be;
+} glue_Addrec;
+
+/* List of added subordinates */
+static glue_Addrec *ga_list;
+static int ga_adding;
+
+static int
+glue_db_init(
+	BackendDB *be,
+	ConfigReply *cr
+)
+{
+	slap_overinst	*on = (slap_overinst *)be->bd_info;
+	slap_overinfo	*oi = on->on_info;
+	BackendInfo	*bi = oi->oi_orig;
+	glueinfo *gi;
+
+	if ( SLAP_GLUE_SUBORDINATE( be )) {
+		Debug( LDAP_DEBUG_ANY, "glue: backend %s is already subordinate, "
+			"cannot have glue overlay!\n",
+			be->be_suffix[0].bv_val, 0, 0 );
+		return LDAP_OTHER;
+	}
+
+	gi = ch_calloc( 1, sizeof(glueinfo));
+	on->on_bi.bi_private = gi;
+	dnParent( be->be_nsuffix, &gi->gi_pdn );
+
+	/* Currently the overlay framework doesn't handle these entry points
+	 * but we need them....
+	 */
+	oi->oi_bi.bi_open = glue_open;
+	oi->oi_bi.bi_close = glue_close;
+
+	/* Only advertise these if the root DB supports them */
+	if ( bi->bi_tool_entry_open )
+		oi->oi_bi.bi_tool_entry_open = glue_tool_entry_open;
+	if ( bi->bi_tool_entry_close )
+		oi->oi_bi.bi_tool_entry_close = glue_tool_entry_close;
+	if ( bi->bi_tool_entry_first )
+		oi->oi_bi.bi_tool_entry_first = glue_tool_entry_first;
+	/* FIXME: check whether all support bi_tool_entry_first_x() ? */
+	if ( bi->bi_tool_entry_first_x )
+		oi->oi_bi.bi_tool_entry_first_x = glue_tool_entry_first_x;
+	if ( bi->bi_tool_entry_next )
+		oi->oi_bi.bi_tool_entry_next = glue_tool_entry_next;
+	if ( bi->bi_tool_entry_get )
+		oi->oi_bi.bi_tool_entry_get = glue_tool_entry_get;
+	if ( bi->bi_tool_dn2id_get )
+		oi->oi_bi.bi_tool_dn2id_get = glue_tool_dn2id_get;
+	if ( bi->bi_tool_entry_put )
+		oi->oi_bi.bi_tool_entry_put = glue_tool_entry_put;
+	if ( bi->bi_tool_entry_reindex )
+		oi->oi_bi.bi_tool_entry_reindex = glue_tool_entry_reindex;
+	if ( bi->bi_tool_entry_modify )
+		oi->oi_bi.bi_tool_entry_modify = glue_tool_entry_modify;
+	if ( bi->bi_tool_sync )
+		oi->oi_bi.bi_tool_sync = glue_tool_sync;
+
+	SLAP_DBFLAGS( be ) |= SLAP_DBFLAG_GLUE_INSTANCE;
+
+	if ( ga_list && ( slapMode & SLAP_SERVER_MODE ) ) {
+		be->bd_info = (BackendInfo *)oi;
+		glue_sub_attach( 1 );
+	}
+
+	return 0;
+}
+
+static int
+glue_db_destroy (
+	BackendDB *be,
+	ConfigReply *cr
+)
+{
+	slap_overinst	*on = (slap_overinst *)be->bd_info;
+	glueinfo		*gi = (glueinfo *)on->on_bi.bi_private;
+
+	free (gi);
+	return SLAP_CB_CONTINUE;
+}
+
+static int
+glue_db_close( 
+	BackendDB *be,
+	ConfigReply *cr
+)
+{
+	slap_overinst	*on = (slap_overinst *)be->bd_info;
+
+	on->on_info->oi_bi.bi_db_close = 0;
+	return 0;
+}
+
+int
+glue_sub_del( BackendDB *b0 )
+{
+	BackendDB *be;
+	int rc = 0;
+
+	/* Find the top backend for this subordinate */
+	be = b0;
+	while ( (be=LDAP_STAILQ_NEXT( be, be_next )) != NULL ) {
+		slap_overinfo *oi;
+		slap_overinst *on;
+		glueinfo *gi;
+		int i;
+
+		if ( SLAP_GLUE_SUBORDINATE( be ))
+			continue;
+		if ( !SLAP_GLUE_INSTANCE( be ))
+			continue;
+		if ( !dnIsSuffix( &b0->be_nsuffix[0], &be->be_nsuffix[0] ))
+			continue;
+
+		/* OK, got the right backend, find the overlay */
+		oi = (slap_overinfo *)be->bd_info;
+		for ( on=oi->oi_list; on; on=on->on_next ) {
+			if ( on->on_bi.bi_type == glue.on_bi.bi_type )
+				break;
+		}
+		assert( on != NULL );
+		gi = on->on_bi.bi_private;
+		for ( i=0; i < gi->gi_nodes; i++ ) {
+			if ( gi->gi_n[i].gn_be == b0 ) {
+				int j;
+
+				for (j=i+1; j < gi->gi_nodes; j++)
+					gi->gi_n[j-1] = gi->gi_n[j];
+
+				gi->gi_nodes--;
+			}
+		}
+	}
+	if ( be == NULL )
+		rc = LDAP_NO_SUCH_OBJECT;
+
+	return rc;
+}
+
+
+/* Attach all the subordinate backends to their superior */
+int
+glue_sub_attach( int online )
+{
+	glue_Addrec *ga, *gnext = NULL;
+	int rc = 0;
+
+	if ( ga_adding )
+		return 0;
+
+	ga_adding = 1;
+
+	/* For all the subordinate backends */
+	for ( ga=ga_list; ga != NULL; ga = gnext ) {
+		BackendDB *be;
+
+		gnext = ga->ga_next;
+
+		/* Find the top backend for this subordinate */
+		be = ga->ga_be;
+		while ( (be=LDAP_STAILQ_NEXT( be, be_next )) != NULL ) {
+			slap_overinfo *oi;
+			slap_overinst *on;
+			glueinfo *gi;
+
+			if ( SLAP_GLUE_SUBORDINATE( be ))
+				continue;
+			if ( !dnIsSuffix( &ga->ga_be->be_nsuffix[0], &be->be_nsuffix[0] ))
+				continue;
+
+			/* If it's not already configured, set up the overlay */
+			if ( !SLAP_GLUE_INSTANCE( be )) {
+				rc = overlay_config( be, glue.on_bi.bi_type, -1, NULL, NULL);
+				if ( rc )
+					break;
+			}
+			/* Find the overlay instance */
+			oi = (slap_overinfo *)be->bd_info;
+			for ( on=oi->oi_list; on; on=on->on_next ) {
+				if ( on->on_bi.bi_type == glue.on_bi.bi_type )
+					break;
+			}
+			assert( on != NULL );
+			gi = on->on_bi.bi_private;
+			gi = (glueinfo *)ch_realloc( gi, sizeof(glueinfo) +
+				gi->gi_nodes * sizeof(gluenode));
+			gi->gi_n[gi->gi_nodes].gn_be = ga->ga_be;
+			dnParent( &ga->ga_be->be_nsuffix[0],
+				&gi->gi_n[gi->gi_nodes].gn_pdn );
+			gi->gi_nodes++;
+			on->on_bi.bi_private = gi;
+			ga->ga_be->be_flags |= SLAP_DBFLAG_GLUE_LINKED;
+			break;
+		}
+		if ( !be ) {
+			Debug( LDAP_DEBUG_ANY, "glue: no superior found for sub %s!\n",
+				ga->ga_be->be_suffix[0].bv_val, 0, 0 );
+			/* allow this for now, assume a superior will
+			 * be added later
+			 */
+			if ( online ) {
+				rc = 0;
+				gnext = ga_list;
+				break;
+			}
+			rc = LDAP_NO_SUCH_OBJECT;
+		}
+		ch_free( ga );
+		if ( rc ) break;
+	}
+
+	ga_list = gnext;
+
+	ga_adding = 0;
+
+	return rc;
+}
+
+int
+glue_sub_add( BackendDB *be, int advert, int online )
+{
+	glue_Addrec *ga;
+	int rc = 0;
+
+	if ( overlay_is_inst( be, "glue" )) {
+		Debug( LDAP_DEBUG_ANY, "glue: backend %s already has glue overlay, "
+			"cannot be a subordinate!\n",
+			be->be_suffix[0].bv_val, 0, 0 );
+		return LDAP_OTHER;
+	}
+	SLAP_DBFLAGS( be ) |= SLAP_DBFLAG_GLUE_SUBORDINATE;
+	if ( advert )
+		SLAP_DBFLAGS( be ) |= SLAP_DBFLAG_GLUE_ADVERTISE;
+
+	ga = ch_malloc( sizeof( glue_Addrec ));
+	ga->ga_next = ga_list;
+	ga->ga_be = be;
+	ga_list = ga;
+
+	if ( online )
+		rc = glue_sub_attach( online );
+
+	return rc;
+}
+
+static int
+glue_access_allowed(
+	Operation		*op,
+	Entry			*e,
+	AttributeDescription	*desc,
+	struct berval		*val,
+	slap_access_t		access,
+	AccessControlState	*state,
+	slap_mask_t		*maskp )
+{
+	BackendDB *b0, *be = glue_back_select( op->o_bd, &e->e_nname );
+	int rc;
+
+	if ( be == NULL || be == op->o_bd || be->bd_info->bi_access_allowed == NULL )
+		return SLAP_CB_CONTINUE;
+
+	b0 = op->o_bd;
+	op->o_bd = be;
+	rc = be->bd_info->bi_access_allowed ( op, e, desc, val, access, state, maskp );
+	op->o_bd = b0;
+	return rc;
+}
+
+int
+glue_sub_init()
+{
+	glue.on_bi.bi_type = "glue";
+
+	glue.on_bi.bi_db_init = glue_db_init;
+	glue.on_bi.bi_db_close = glue_db_close;
+	glue.on_bi.bi_db_destroy = glue_db_destroy;
+
+	glue.on_bi.bi_op_search = glue_op_search;
+	glue.on_bi.bi_op_modify = glue_op_func;
+	glue.on_bi.bi_op_modrdn = glue_op_func;
+	glue.on_bi.bi_op_add = glue_op_func;
+	glue.on_bi.bi_op_delete = glue_op_func;
+	glue.on_bi.bi_op_abandon = glue_op_abandon;
+	glue.on_bi.bi_extended = glue_op_func;
+
+	glue.on_bi.bi_chk_referrals = glue_chk_referrals;
+	glue.on_bi.bi_chk_controls = glue_chk_controls;
+	glue.on_bi.bi_entry_get_rw = glue_entry_get_rw;
+	glue.on_bi.bi_entry_release_rw = glue_entry_release_rw;
+	glue.on_bi.bi_access_allowed = glue_access_allowed;
+
+	glue.on_response = glue_response;
+
+	return overlay_register( &glue );
+}