X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=servers%2Fslapd%2Fbackglue.c;h=f0ab5ca02dadc5bbd6231aee7ada458dc32fa8d7;hb=843e327a39e1ba023001fbbbe89733a431956549;hp=cf81ce92146e8ade78af1d7b5f47926cd8983722;hpb=1586a68219cf85e9caaafcf2259c9bc249358077;p=openldap

diff --git a/servers/slapd/backglue.c b/servers/slapd/backglue.c
index cf81ce9214..f0ab5ca02d 100644
--- a/servers/slapd/backglue.c
+++ b/servers/slapd/backglue.c
@@ -1,8 +1,8 @@
-/* backglue.c - backend glue routines */
+/* backglue.c - backend glue */
 /* $OpenLDAP$ */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 2001-2003 The OpenLDAP Foundation.
+ * Copyright 2001-2007 The OpenLDAP Foundation.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -19,18 +19,10 @@
  * 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.
  *
- * This uses the backend structures and routines extensively, but is
- * not an actual backend of its own. To use it you must add a "subordinate"
- * keyword to the configuration of other backends. Subordinates will
- * automatically be connected to their parent backend.
- *
  * 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 and rootpw.
- *
- * If you need more elaborate configuration, you probably should be using
- * back-meta instead.
+ * of the glued backends should have identical rootdn.
  *  -- Howard Chu
  */
 
@@ -45,162 +37,83 @@
 #include "slap.h"
 
 typedef struct gluenode {
-	BackendDB *be;
-	struct berval pdn;
+	BackendDB *gn_be;
+	struct berval gn_pdn;
 } gluenode;
 
 typedef struct glueinfo {
-	BackendInfo bi;
-	BackendDB bd;
-	int nodes;
-	gluenode n[1];
+	int gi_nodes;
+	struct berval gi_pdn;
+	gluenode gi_n[1];
 } glueinfo;
 
+static slap_overinst	glue;
+
 static int glueMode;
 static BackendDB *glueBack;
 
-static slap_response glue_back_response;
+static slap_response glue_op_response;
 
 /* Just like select_backend, but only for our backends */
 static BackendDB *
 glue_back_select (
 	BackendDB *be,
-	const char *dn
+	struct berval *dn
 )
 {
-	glueinfo *gi = (glueinfo *) be->bd_info;
-	struct berval bv;
+	slap_overinst	*on = (slap_overinst *)be->bd_info;
+	glueinfo		*gi = (glueinfo *)on->on_bi.bi_private;
 	int i;
 
-	bv.bv_len = strlen(dn);
-	bv.bv_val = (char *) dn;
+	for (i = gi->gi_nodes-1; i >= 0; i--) {
+		assert( gi->gi_n[i].gn_be->be_nsuffix != NULL );
 
-	for (i = 0; i<gi->nodes; i++) {
-		if (dnIsSuffix(&bv, &gi->n[i].be->be_nsuffix[0])) {
-			return gi->n[i].be;
+		if (dnIsSuffix(dn, &gi->gi_n[i].gn_be->be_nsuffix[0])) {
+			return gi->gi_n[i].gn_be;
 		}
 	}
-	return NULL;
-}
-
-/* This function will only be called in tool mode */
-static int
-glue_back_open (
-	BackendInfo *bi
-)
-{
-	int rc = 0;
-	static int glueOpened = 0;
-
-	if (glueOpened) return 0;
-
-	glueOpened = 1;
-
-	/* If we were invoked in tool mode, open all the underlying backends */
-	if (slapMode & SLAP_TOOL_MODE) {
-		rc = backend_startup (NULL);
-	} /* other case is impossible */
-	return rc;
+	be->bd_info = on->on_info->oi_orig;
+	return be;
 }
 
-/* This function will only be called in tool mode */
-static int
-glue_back_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_back_db_open (
-	BackendDB *be
-)
-{
-	glueinfo *gi = (glueinfo *) be->bd_info;
-	static int glueOpened = 0;
-	int rc = 0;
-
-	if (glueOpened) return 0;
-
-	glueOpened = 1;
-
-	gi->bd.be_acl = be->be_acl;
-
-	if (gi->bd.bd_info->bi_db_open)
-		rc = gi->bd.bd_info->bi_db_open(&gi->bd);
-
-	return rc;
-}
-
-static int
-glue_back_db_close (
-	BackendDB *be
-)
-{
-	glueinfo *gi = (glueinfo *) be->bd_info;
-	static int glueClosed = 0;
-
-	if (glueClosed) return 0;
-
-	glueClosed = 1;
-
-	/* Close the master */
-	if (gi->bd.bd_info->bi_db_close)
-		gi->bd.bd_info->bi_db_close( &gi->bd );
-
-	return 0;
-}
-
-static int
-glue_back_db_destroy (
-	BackendDB *be
-)
-{
-	glueinfo *gi = (glueinfo *) be->bd_info;
-
-	if (gi->bd.bd_info->bi_db_destroy)
-		gi->bd.bd_info->bi_db_destroy( &gi->bd );
-	free (gi);
-	return 0;
-}
 
 typedef struct glue_state {
+	char *matched;
+	BerVarray refs;
+	LDAPControl **ctrls;
 	int err;
-	int slimit;
 	int matchlen;
-	char *matched;
 	int nrefs;
-	BerVarray refs;
+	int nctrls;
 } glue_state;
 
 static int
-glue_back_response ( Operation *op, SlapReply *rs )
+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:
-		if ( rs->sr_nentries >= gs->slimit ) {
-			gs->err = LDAP_SIZELIMIT_EXCEEDED;
-			return -1;
-		}
-		/* fallthru */
 	case REP_SEARCHREF:
+	case REP_INTERMEDIATE:
 		return SLAP_CB_CONTINUE;
 
 	default:
-		if (rs->sr_err == LDAP_SUCCESS || gs->err != LDAP_SUCCESS)
+		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);
@@ -237,39 +150,204 @@ glue_back_response ( Operation *op, SlapReply *rs )
 			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 = ch_malloc((i+1)*sizeof(LDAPControl *));
+			} else {
+				newctrls = ch_realloc(gs->ctrls,
+					(j+i+1)*sizeof(LDAPControl *));
+			}
+			for (k=0; k<i; j++,k++) {
+				newctrls[j] = ch_malloc(sizeof(LDAPControl));
+				*newctrls[j] = *rs->sr_ctrls[k];
+				if ( !BER_BVISNULL( &rs->sr_ctrls[k]->ldctl_value ))
+					ber_dupbv( &newctrls[j]->ldctl_value,
+						&rs->sr_ctrls[k]->ldctl_value );
+			}
+			newctrls[j] = NULL;
+			gs->nctrls = j;
+			gs->ctrls = newctrls;
+		}
 	}
 	return 0;
 }
 
 static int
-glue_back_search ( Operation *op, SlapReply *rs )
+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 master 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_response ( Operation *op, SlapReply *rs )
+{
+	slap_overinst	*on = (slap_overinst *)op->o_bd->bd_info;
+	BackendDB *be = op->o_bd;
+	be = glue_back_select (op->o_bd, &op->o_req_ndn);
+
+	/* If we're on the master 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;
-	glueinfo *gi = (glueinfo *) b0->bd_info;
+	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 master 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 master 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 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;
-	glue_state gs = {0, 0, 0, NULL, 0, NULL};
-	slap_callback cb = { NULL, glue_back_response, NULL, NULL };
-	int scope0, slimit0, tlimit0;
-	struct berval dn, ndn;
+	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;
 
-	if (op->ors_tlimit) {
-		stoptime = slap_get_time () + op->ors_tlimit;
-	}
+	starttime = op->o_time;
+	stoptime = slap_get_time () + op->ors_tlimit;
+
+	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:
-		op->o_bd = glue_back_select (b0, op->o_req_ndn.bv_val);
+		if ( op->o_bd == b0 )
+			return SLAP_CB_CONTINUE;
 
+		rs->sr_err = LDAP_UNWILLING_TO_PERFORM;
 		if (op->o_bd && op->o_bd->be_search) {
 			rs->sr_err = op->o_bd->be_search( op, rs );
-		} else {
-			send_ldap_error(op, rs, LDAP_UNWILLING_TO_PERFORM,
-				      "No search target found");
 		}
 		return rs->sr_err;
 
@@ -279,56 +357,79 @@ glue_back_search ( Operation *op, SlapReply *rs )
 		op->o_callback = &cb;
 		rs->sr_err = gs.err = LDAP_UNWILLING_TO_PERFORM;
 		scope0 = op->ors_scope;
-		slimit0 = gs.slimit = op->ors_slimit;
 		tlimit0 = op->ors_tlimit;
 		dn = op->o_req_dn;
 		ndn = op->o_req_ndn;
+		b1 = op->o_bd;
 
 		/*
-		 * Execute in reverse order, most general first 
+		 * Execute in reverse order, most specific first 
 		 */
-		for (i = gi->nodes-1; i >= 0; i--) {
-			if (!gi->n[i].be || !gi->n[i].be->be_search)
+		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 (tlimit0) {
-				op->ors_tlimit = stoptime - slap_get_time ();
+			if (!dnIsSuffix(&btmp->be_nsuffix[0], &b1->be_nsuffix[0]))
+				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;
 				}
 			}
-			if (slimit0) {
-				op->ors_slimit = slimit0 - rs->sr_nentries;
-				if (op->ors_slimit < 0) {
-					rs->sr_err = gs.err = LDAP_SIZELIMIT_EXCEEDED;
-					break;
-				}
-			}
 			rs->sr_err = 0;
 			/*
 			 * check for abandon 
 			 */
 			if (op->o_abandon) {
-				goto done;
+				goto end_of_loop;
 			}
-			op->o_bd = gi->n[i].be;
+			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(&gi->n[i].pdn, &ndn))
+				dn_match(pdn, &ndn))
 			{
 				op->ors_scope = LDAP_SCOPE_BASE;
 				op->o_req_dn = op->o_bd->be_suffix[0];
 				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;
+				op->o_req_dn = dn;
+				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))
 			{
 				op->o_req_dn = op->o_bd->be_suffix[0];
 				op->o_req_ndn = op->o_bd->be_nsuffix[0];
-				rs->sr_err = op->o_bd->be_search( op, rs );
+				rs->sr_err = glue_sub_search( op, rs, b0, on );
+				if ( rs->sr_err == LDAP_NO_SUCH_OBJECT ) {
+					gs.err = LDAP_SUCCESS;
+				}
+				op->o_req_dn = dn;
+				op->o_req_ndn = ndn;
 
 			} else if (dnIsSuffix(&ndn, &op->o_bd->be_nsuffix[0])) {
-				rs->sr_err = op->o_bd->be_search( op, rs );
+				rs->sr_err = glue_sub_search( op, rs, b0, on );
 			}
 
 			switch ( gs.err ) {
@@ -340,6 +441,10 @@ glue_back_search ( Operation *op, SlapReply *rs )
 			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;
 			
 			default:
@@ -348,29 +453,43 @@ glue_back_search ( Operation *op, SlapReply *rs )
 		}
 end_of_loop:;
 		op->ors_scope = scope0;
-		op->ors_slimit = slimit0;
 		op->ors_tlimit = tlimit0;
+		op->o_time = starttime;
 		op->o_req_dn = dn;
 		op->o_req_ndn = ndn;
 
 		break;
 	}
-	op->o_callback = cb.sc_next;
-	rs->sr_err = gs.err;
-	rs->sr_matched = gs.matched;
-	rs->sr_ref = gs.refs;
-
-	send_ldap_result( op, rs );
+	if ( op->o_abandon ) {
+		rs->sr_err = SLAPD_ABANDON;
+	} else {
+		op->o_callback = cb.sc_next;
+		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 );
+	}
 
-done:
 	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; ) {
+			if (!BER_BVISNULL( &gs.ctrls[i]->ldctl_value ))
+				free(gs.ctrls[i]->ldctl_value.bv_val);
+			free(gs.ctrls[i]);
+		}
+		free(gs.ctrls);
+	}
 	return rs->sr_err;
 }
 
+static BackendDB toolDB;
 
 static int
 glue_tool_entry_open (
@@ -378,12 +497,16 @@ glue_tool_entry_open (
 	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;
 
 	return 0;
 }
@@ -403,26 +526,144 @@ glue_tool_entry_close (
 	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;
+
+	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 );
+			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_release_rw (
+	Operation *op,
+	Entry *e,
+	int rw
+)
+{
+	BackendDB *b0, b2;
+	int rc = -1;
+
+	b0 = op->o_bd;
+	b2 = *op->o_bd;
+	b2.bd_info = (BackendInfo *)glue_tool_inst( op->o_bd->bd_info );
+	op->o_bd = glue_back_select (&b2, &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 ID
 glue_tool_entry_first (
 	BackendDB *b0
 )
 {
-	glueinfo *gi = (glueinfo *) b0->bd_info;
+	slap_overinst	*on = glue_tool_inst( b0->bd_info );
+	glueinfo		*gi = on->on_bi.bi_private;
 	int i;
 
 	/* If we're starting from scratch, start at the most general */
 	if (!glueBack) {
-		for (i = gi->nodes-1; i >= 0; i--) {
-			if (gi->n[i].be->be_entry_open &&
-			    gi->n[i].be->be_entry_first) {
-			    	glueBack = gi->n[i].be;
-				break;
+		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, glueMode) != 0)
+	if (!glueBack || !glueBack->be_entry_open || !glueBack->be_entry_first ||
+		glueBack->be_entry_open (glueBack, glueMode) != 0)
 		return NOID;
 
 	return glueBack->be_entry_first (glueBack);
@@ -433,7 +674,8 @@ glue_tool_entry_next (
 	BackendDB *b0
 )
 {
-	glueinfo *gi = (glueinfo *) b0->bd_info;
+	slap_overinst	*on = glue_tool_inst( b0->bd_info );
+	glueinfo		*gi = on->on_bi.bi_private;
 	int i;
 	ID rc;
 
@@ -443,17 +685,18 @@ glue_tool_entry_next (
 	rc = glueBack->be_entry_next (glueBack);
 
 	/* If we ran out of entries in one database, move on to the next */
-	if (rc == NOID) {
-		glueBack->be_entry_close (glueBack);
-		for (i=0; i<gi->nodes; i++) {
-			if (gi->n[i].be == 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 = NULL;
-			rc = NOID;
+			break;
 		} else {
-			glueBack = gi->n[i-1].be;
+			glueBack = gi->gi_n[i-1].gn_be;
 			rc = glue_tool_entry_first (b0);
 		}
 	}
@@ -479,26 +722,38 @@ glue_tool_entry_put (
 	struct berval *text
 )
 {
-	BackendDB *be;
-	int rc;
+	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;
 
-	be = glue_back_select (b0, e->e_ndn);
 	if (!be->be_entry_put)
 		return NOID;
 
 	if (!glueBack) {
-		rc = be->be_entry_open (be, glueMode);
-		if (rc != 0)
+		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.
 		 */
-		glueBack->be_entry_close (glueBack);
-		rc = be->be_entry_open (be, glueMode);
-		if (rc != 0)
+		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);
@@ -521,106 +776,264 @@ glue_tool_sync (
 	BackendDB *b0
 )
 {
-	glueinfo *gi = (glueinfo *) b0->bd_info;
+	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->nodes; i++)
-		if (gi->n[i].be->be_sync)
-			gi->n[i].be->be_sync (gi->n[i].be);
+	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;
 }
 
-int
-glue_sub_init( )
+static int
+glue_db_init(
+	BackendDB *be
+)
 {
-	int i, j;
-	int cont = num_subordinates;
-	BackendDB *b1, *be;
-	BackendInfo *bi = NULL;
+	slap_overinst	*on = (slap_overinst *)be->bd_info;
+	slap_overinfo	*oi = on->on_info;
+	BackendInfo	*bi = oi->oi_orig;
 	glueinfo *gi;
 
-	/* While there are subordinate backends, search backwards through the
-	 * backends and connect them to their superior.
+	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....
 	 */
-	for (i = nBackendDB - 1, b1=&backendDB[i]; cont && i>=0; b1--,i--) {
-		if (SLAP_GLUE_SUBORDINATE ( b1 ) ) {
-			/* The last database cannot be a subordinate of noone */
-			if (i == nBackendDB - 1) {
-				b1->be_flags ^= SLAP_BFLAG_GLUE_SUBORDINATE;
-			}
+	oi->oi_bi.bi_open = glue_open;
+	oi->oi_bi.bi_close = glue_close;
+
+	oi->oi_bi.bi_entry_release_rw = glue_entry_release_rw;
+
+	/* 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;
+	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_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_sync )
+		oi->oi_bi.bi_tool_sync = glue_tool_sync;
+
+	/*FIXME : need to add support */
+	oi->oi_bi.bi_tool_dn2id_get = 0;
+	oi->oi_bi.bi_tool_id2entry_get = 0;
+	oi->oi_bi.bi_tool_entry_modify = 0;
+
+	SLAP_DBFLAGS( be ) |= SLAP_DBFLAG_GLUE_INSTANCE;
+
+	return 0;
+}
+
+static int
+glue_db_destroy (
+	BackendDB *be
+)
+{
+	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
+)
+{
+	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;
 		}
-		gi = NULL;
-		for (j = i-1, be=&backendDB[j]; j>=0; be--,j--) {
-			if ( ! SLAP_GLUE_SUBORDINATE( be ) ) {
-				continue;
+		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--;
 			}
-			/* We will only link it once */
-			if ( SLAP_GLUE_LINKED( be ) ) {
+		}
+	}
+	if ( be == NULL )
+		rc = LDAP_NO_SUCH_OBJECT;
+
+	return rc;
+}
+
+typedef struct glue_Addrec {
+	struct glue_Addrec *ga_next;
+	BackendDB *ga_be;
+} glue_Addrec;
+
+/* List of added subordinates */
+static glue_Addrec *ga_list;
+
+/* Attach all the subordinate backends to their superior */
+int
+glue_sub_attach()
+{
+	glue_Addrec *ga, *gnext = NULL;
+	int rc = 0;
+
+	/* 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(&be->be_nsuffix[0], &b1->be_nsuffix[0])) {
+			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 );
+				if ( rc )
+					break;
 			}
-			cont--;
-			be->be_flags |= SLAP_BFLAG_GLUE_LINKED;
-			if (gi == NULL) {
-				/* We create a copy of the superior's be
-				 * structure, pointing to all of its original
-				 * information. Then we replace elements of
-				 * the superior's info with our own. The copy
-				 * is used whenever we have operations to pass
-				 * down to the real database.
-				 */
-				b1->be_flags |= SLAP_BFLAG_GLUE_INSTANCE;
-				gi = (glueinfo *)ch_malloc(sizeof(glueinfo));
-				gi->nodes = 0;
-				gi->bd = *b1;
-				gi->bi = *b1->bd_info;
-				bi = (BackendInfo *)gi;
-				bi->bi_open = glue_back_open;
-				bi->bi_close = glue_back_close;
-				bi->bi_db_open = glue_back_db_open;
-				bi->bi_db_close = glue_back_db_close;
-				bi->bi_db_destroy = glue_back_db_destroy;
-
-				bi->bi_op_search = glue_back_search;
-
-				/*
-				 * hooks for slap tools
-				 */
-				bi->bi_tool_entry_open = glue_tool_entry_open;
-				bi->bi_tool_entry_close = glue_tool_entry_close;
-				bi->bi_tool_entry_first = glue_tool_entry_first;
-				bi->bi_tool_entry_next = glue_tool_entry_next;
-				bi->bi_tool_entry_get = glue_tool_entry_get;
-				bi->bi_tool_entry_put = glue_tool_entry_put;
-				bi->bi_tool_entry_reindex = glue_tool_entry_reindex;
-				bi->bi_tool_sync = glue_tool_sync;
-				/* FIXME : will support later */
-				bi->bi_tool_dn2id_get = 0;
-				bi->bi_tool_id2entry_get = 0;
-				bi->bi_tool_entry_modify = 0;
-			} else {
-				gi = (glueinfo *)ch_realloc(gi,
-					sizeof(glueinfo) +
-					gi->nodes * sizeof(gluenode));
+			/* 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;
 			}
-			gi->n[gi->nodes].be = be;
-			dnParent( &be->be_nsuffix[0], &gi->n[gi->nodes].pdn ); 
-			gi->nodes++;
+			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;
+			break;
 		}
-		if (gi) {
-			/* One more node for the master */
-			gi = (glueinfo *)ch_realloc(gi,
-				sizeof(glueinfo) + gi->nodes * sizeof(gluenode));
-			gi->n[gi->nodes].be = &gi->bd;
-			dnParent( &b1->be_nsuffix[0], &gi->n[gi->nodes].pdn );
-			gi->nodes++;
-			b1->bd_info = (BackendInfo *)gi;
+		if ( !be ) {
+			Debug( LDAP_DEBUG_ANY, "glue: no superior found for sub %s!\n",
+				ga->ga_be->be_suffix[0].bv_val, 0, 0 );
+			rc = LDAP_NO_SUCH_OBJECT;
 		}
+		ch_free( ga );
+		if ( rc ) break;
 	}
-	/* If there are any unresolved subordinates left, something is wrong */
-	return cont;
+
+	ga_list = gnext;
+
+	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();
+
+	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_extended = glue_op_func;
+
+	glue.on_bi.bi_chk_referrals = glue_chk_referrals;
+	glue.on_bi.bi_chk_controls = glue_chk_controls;
+	glue.on_response = glue_response;
+
+	return overlay_register( &glue );
 }