Added translucent overlay (sponsored by HP)

doc/man/man5/slapo-translucent.5

+.TH SLAPO-TRANSLUCENT 5 "RELEASEDATE" "OpenLDAP LDVERSION"
+.\" Copyright 2004 The OpenLDAP Foundation All Rights Reserved.
+.\" Copying restrictions apply.  See COPYRIGHT/LICENSE.
+.\" $OpenLDAP$
+.SH NAME
+slapo-translucent \- Proxy Override overlay
+.SH SYNOPSIS
+ETCDIR/slapd.conf
+.SH DESCRIPTION
+The Proxy Override overlay can be used with a backend database such as
+.BR slapd-bdb (5)
+to create a "translucent proxy".  Entries retrieved from a remote LDAP
+server may have some or all attributes overridden, or new attributes
+added, by entries in the local database before being presented to the
+client.
+.LP
+A
+.BR search
+operation is first populated with entries from the remote LDAP server, the
+attributes of which are then overridden with any attributes defined in the
+local database. Local overrides may be populated with the
+.BR add ,
+.B modify ,
+and
+.B modrdn
+operations, the use of which is restricted to the root user.
+.LP
+A
+.BR compare
+operation will perform a comparison with attributes defined in the local
+database record (if any) before any comparison is made with data in the
+remote database.
+.SH CONFIGURATION
+The Proxy Override overlay uses a remote LDAP server which is configured
+with the options shown in
+.BR slapd-ldap (5).
+These
+.B slapd.conf
+options are specific to the Proxy Override overlay; they may appear anywhere
+after the
+.B overlay
+directive and before any subsequent
+.B database
+directive.
+.TP
+.B translucent_strict
+By default, attempts to delete attributes in either the local or remote
+databases will be silently ignored. The
+.B translucent_strict
+directive causes these modifications to fail with a Constraint Violation.
+.TP
+.B translucent_no_glue
+This configuration option disables the automatic creation of "glue" records
+for an
+.B add
+or
+.B modrdn
+operation, such that all parents of an entry added to the local database
+must be created by hand. Glue records are always created for a
+.B modify
+operation.
+.SH CAVEATS
+.LP
+The Proxy Override overlay will disable schema checking in the local database,
+so that an entry consisting of overlay attributes need not adhere to the
+complete schema.
+.LP
+Because the translucent overlay does not perform any DN rewrites,  the local
+and remote database instances must have the same suffix.  Other configurations
+will probably fail with No Such Object and other errors.
+.SH FILES
+.TP
+ETCDIR/slapd.conf
+default slapd configuration file
+.SH SEE ALSO
+.BR slapd.conf (5),
+.BR slapd-ldap (5).

servers/slapd/overlays/Makefile.in

@@ -23,6 +23,7 @@ SRCS = overlays.c \
 	refint.c \
 	rwm.c rwmconf.c rwmdn.c rwmmap.c \
 	syncprov.c \
+	translucent.c \
 	unique.c
 OBJS = overlays.lo \
 	denyop.lo \
@@ -34,6 +35,7 @@ OBJS = overlays.lo \
 	refint.lo \
 	rwm.lo rwmconf.lo rwmdn.lo rwmmap.lo \
 	syncprov.lo \
+	translucent.lo \
 	unique.lo
 
 LDAP_INCDIR= ../../../include       
@@ -78,6 +80,9 @@ rwm.la : rwm.lo $(@PLAT@_LINK_LIBS)
 syncprov.la : syncprov.lo $(@PLAT@_LINK_LIBS)
 	$(LTLINK_MOD) -module -o $@ syncprov.lo version.lo $(LINK_LIBS)
 
+translucent.la : translucent.lo $(@PLAT@_LINK_LIBS)
+	$(LTLINK_MOD) -module -o $@ translucent.lo version.lo $(LINK_LIBS)
+
 unique.la : unique.lo $(@PLAT@_LINK_LIBS)
 	$(LTLINK_MOD) -module -o $@ unique.lo version.lo $(LINK_LIBS)
 

servers/slapd/overlays/overlays.c

@@ -50,6 +50,9 @@ extern int rwm_init();
 #if SLAPD_OVER_SYNCPROV == SLAPD_MOD_STATIC
 extern int syncprov_init();
 #endif
+#if SLAPD_OVER_TRANSLUCENT == SLAPD_MOD_STATIC
+extern int translucent_init();
+#endif
 #if SLAPD_OVER_UNIQUE == SLAPD_MOD_STATIC
 extern int unique_init();
 #endif
@@ -85,6 +88,9 @@ static struct {
 #if SLAPD_OVER_SYNCPROV == SLAPD_MOD_STATIC
 	{ "Syncrepl Provider", syncprov_init },
 #endif
+#if SLAPD_OVER_TRANSLUCENT == SLAPD_MOD_STATIC
+	{ "Translucent Proxy", translucent_init },
+#endif
 #if SLAPD_OVER_UNIQUE == SLAPD_MOD_STATIC
 	{ "Attribute Uniqueness", unique_init },
 #endif

servers/slapd/overlays/translucent.c

+/* Copyright 2004, Symas Corporation.
+ * All Rights Reserved.
+ */
+
+#include "portable.h"
+
+#ifdef SLAPD_OVER_TRANSLUCENT
+
+#include <stdio.h>
+
+#include <ac/string.h>
+#include <ac/socket.h>
+
+#include "slap.h"
+
+/* config block */
+
+typedef struct translucent_configuration {
+	int debug;
+	int strict;
+	int no_add;
+	int glue;
+} translucent_configuration;
+
+/* stack of captive backends */
+
+typedef struct overlay_stack {
+	BackendInfo *info;			/* captive backend */
+	void *private;				/* local backend_private */
+	translucent_configuration *config;	/* our_private: configuration */
+} overlay_stack;
+
+/* for translucent_init() */
+
+static slap_overinst translucent;
+
+/*
+** glue_parent()
+**	call syncrepl_add_glue() with the parent suffix;
+**
+*/
+
+static struct berval glue[] = { BER_BVC("top"), BER_BVC("glue"), BER_BVNULL };
+
+void glue_parent(Operation *op) {
+	Operation nop = *op;
+	slap_overinst *on = (slap_overinst *) op->o_bd->bd_info;
+	struct berval dn = { 0, NULL };
+	char *odn = op->o_req_ndn.bv_val;
+	Attribute *a;
+	Entry *e;
+	int idn, ldn;
+
+	/* tis more work to use strchr() for a berval... */
+	for(idn = 0; odn[idn] && odn[idn] != ','; idn++);
+	if(!idn || !odn[idn]) return;   /* because you never know */
+	idn++;
+	ldn = dn.bv_len = op->o_req_ndn.bv_len - idn;
+	dn.bv_val = ch_malloc(ldn + 1);
+	strcpy(dn.bv_val, odn + idn);
+
+	Debug(LDAP_DEBUG_TRACE, "=> glue_parent: fabricating glue for <%s>\n", dn.bv_val, 0, 0);
+
+	e = ch_calloc(1, sizeof(Entry));
+	e->e_id = NOID;
+	ber_dupbv(&e->e_name, &dn);
+	ber_dupbv(&e->e_nname, &dn);
+
+	a = ch_calloc(1, sizeof(Attribute));
+	a->a_desc = slap_schema.si_ad_objectClass;
+	a->a_vals = ch_malloc(sizeof(struct berval) * 3);
+	ber_dupbv(&a->a_vals[0], &glue[0]);
+	ber_dupbv(&a->a_vals[1], &glue[1]);
+	ber_dupbv(&a->a_vals[2], &glue[2]);
+	a->a_nvals = a->a_vals;
+	a->a_next = e->e_attrs;
+	e->e_attrs = a;
+
+	a = ch_calloc(1, sizeof(Attribute));
+	a->a_desc = slap_schema.si_ad_structuralObjectClass;
+	a->a_vals = ch_malloc(sizeof(struct berval) * 2);
+	ber_dupbv(&a->a_vals[0], &glue[1]);
+	ber_dupbv(&a->a_vals[1], &glue[2]);
+	a->a_nvals = a->a_vals;
+	a->a_next = e->e_attrs;
+	e->e_attrs = a;
+
+	nop.o_req_dn = dn;
+	nop.o_req_ndn = dn;
+	nop.ora_e = e;
+	nop.o_bd->bd_info = (BackendInfo *) on->on_info->oi_orig;
+
+	syncrepl_add_glue(&nop, e);
+	return;
+}
+
+/*
+** dup_bervarray()
+**	copy a BerVarray;
+*/
+
+BerVarray dup_bervarray(BerVarray b) {
+	int i, len;
+	BerVarray nb;
+	for(len = 0; b[len].bv_val; len++);
+	nb = ch_malloc((len+1) * sizeof(BerValue));
+	for(i = 0; i < len; i++) ber_dupbv(&nb[i], &b[i]);
+	nb[len].bv_val = NULL;
+	nb[len].bv_len = 0;
+	return(nb);
+}
+
+/*
+** free_attr_chain()
+**	free only the Attribute*, not the contents;
+**
+*/
+void free_attr_chain(Attribute *a) {
+	Attribute *ax;
+	for(ax = NULL; a; a = a->a_next) {
+		if(ax) ch_free(ax);
+		ax = a;
+	}
+	return;
+}
+
+/*
+** translucent_add()
+**	if not bound as root, send ACCESS error;
+**	if config.glue, glue_parent();
+**	return CONTINUE;
+**
+*/
+
+static int translucent_add(Operation *op, SlapReply *rs) {
+	slap_overinst *on = (slap_overinst *) op->o_bd->bd_info;
+	overlay_stack *ov = on->on_bi.bi_private;
+	Debug(LDAP_DEBUG_TRACE, "==> translucent_add: %s\n",
+		op->o_req_dn.bv_val, 0, 0);
+	if(!be_isroot(op)) {
+		op->o_bd->bd_info = (BackendInfo *) on->on_info;
+		send_ldap_error(op, rs, LDAP_INSUFFICIENT_ACCESS,
+			"user modification of overlay database not permitted");
+		return(rs->sr_err);
+	}
+	if(!ov->config->glue) glue_parent(op);
+	return(SLAP_CB_CONTINUE);
+}
+
+/*
+** translucent_modrdn()
+**	if not bound as root, send ACCESS error;
+**	if !config.glue, glue_parent();
+**	else return CONTINUE;
+**
+*/
+
+static int translucent_modrdn(Operation *op, SlapReply *rs) {
+	slap_overinst *on = (slap_overinst *) op->o_bd->bd_info;
+	overlay_stack *ov = on->on_bi.bi_private;
+	Debug(LDAP_DEBUG_TRACE, "==> translucent_modrdn: %s -> %s\n",
+		op->o_req_dn.bv_val, op->orr_newrdn.bv_val, 0);
+	if(!be_isroot(op)) {
+		op->o_bd->bd_info = (BackendInfo *) on->on_info;
+		send_ldap_error(op, rs, LDAP_INSUFFICIENT_ACCESS,
+			"user modification of overlay database not permitted");
+		return(rs->sr_err);
+	}
+	if(!ov->config->glue) glue_parent(op);
+	return(SLAP_CB_CONTINUE);
+}
+
+/*
+** translucent_delete()
+**	if not bound as root, send ACCESS error;
+**	else return CONTINUE;
+**
+*/
+
+static int translucent_delete(Operation *op, SlapReply *rs) {
+	slap_overinst *on = (slap_overinst *) op->o_bd->bd_info;
+	Debug(LDAP_DEBUG_TRACE, "==> translucent_delete: %s\n",
+		op->o_req_dn.bv_val, 0, 0);
+	if(!be_isroot(op)) {
+		op->o_bd->bd_info = (BackendInfo *) on->on_info;
+		send_ldap_error(op, rs, LDAP_INSUFFICIENT_ACCESS,
+			"user modification of overlay database not permitted");
+		return(rs->sr_err);
+	}
+	return(SLAP_CB_CONTINUE);
+}
+
+/*
+** translucent_modify()
+**	modify in local backend if exists in both;
+**	otherwise, add to local backend;
+**	fail if not defined in captive backend;
+**
+*/
+
+static int translucent_modify(Operation *op, SlapReply *rs) {
+	SlapReply nrs = { REP_RESULT };
+	Operation nop = *op;
+
+	slap_overinst *on = (slap_overinst *) op->o_bd->bd_info;
+	overlay_stack *ov = on->on_bi.bi_private;
+	translucent_configuration *cf = ov->config;
+	void *private = op->o_bd->be_private;
+	Entry ne, *e, *re = NULL;
+	Attribute *a, *ax;
+	Modifications *m, *mm;
+	int del, rc, erc = 0;
+
+	Debug(LDAP_DEBUG_TRACE, "==> translucent_modify: %s\n",
+		op->o_req_dn.bv_val, 0, 0);
+
+/*
+** fetch entry from the captive backend;
+** if it did not exist, fail;
+** release it, if captive backend supports this;
+**
+*/
+
+	op->o_bd->bd_info = (BackendInfo *) on->on_info;
+	op->o_bd->be_private = ov->private;
+	rc = ov->info->bi_entry_get_rw(op, &op->o_req_ndn, NULL, NULL, 0, &re);
+	op->o_bd->be_private = private;
+
+	/* if(ov->config->no_add && (!re || rc != LDAP_SUCCESS)) */
+	if(!re || rc != LDAP_SUCCESS) {
+		send_ldap_error(op, rs, LDAP_NO_SUCH_OBJECT,
+			"attempt to modify nonexistent local record");
+		return(rs->sr_err);
+	}
+
+/*
+** fetch entry from local backend;
+** if it exists:
+**	foreach Modification:
+**	    if attr not present in local:
+**		if Mod == LDAP_MOD_DELETE:
+**		    if remote attr not present, return NO_SUCH;
+**		    if remote attr present, drop this Mod;
+**		else force this Mod to LDAP_MOD_ADD;
+**	return CONTINUE;
+**
+*/
+
+	rc = be_entry_get_rw(op, &op->o_req_ndn, NULL, NULL, 0, &e);
+
+	if(e && rc == LDAP_SUCCESS) {
+		Debug(LDAP_DEBUG_TRACE, "=> translucent_modify: found local entry\n", 0, 0, 0);
+		for(m = op->orm_modlist; m; m = m->sml_next) {
+			for(a = e->e_attrs; a; a = a->a_next)
+				if(a->a_desc == m->sml_desc) break;
+			if(a) continue;		/* found local attr */
+			if(m->sml_op == LDAP_MOD_DELETE) {
+				for(a = re->e_attrs; a; a = a->a_next)
+					if(a->a_desc == m->sml_desc) break;
+				/* not found remote attr */
+				if(!a) {
+					erc = LDAP_NO_SUCH_ATTRIBUTE;
+					goto release;
+				}
+				if(ov->config->strict) {
+					erc = LDAP_CONSTRAINT_VIOLATION;
+					goto release;
+				}
+				Debug(LDAP_DEBUG_TRACE,
+					"=> translucent_modify: silently dropping delete: %s\n",
+					m->sml_desc->ad_cname.bv_val, 0, 0);
+				for(mm = op->orm_modlist; mm->sml_next != m; mm = mm->sml_next);
+				mm->sml_next = m->sml_next;
+				mm = m;
+				m = m->sml_next;
+				mm->sml_next = NULL;		/* hack */
+				slap_mods_free(mm);
+				if(m) continue;
+			}
+			m->sml_op = LDAP_MOD_ADD;
+		}
+		erc = SLAP_CB_CONTINUE;
+release:
+		if(re) {
+			op->o_bd->be_private = ov->private;
+			if(ov->info->bi_entry_release_rw)
+				ov->info->bi_entry_release_rw(op, re, 0);
+			else
+				entry_free(re);
+			op->o_bd->be_private = private;
+		}
+		be_entry_release_r(op, e);
+		if(erc == SLAP_CB_CONTINUE) {
+			op->o_bd->bd_info = (BackendInfo *) on;
+			return(erc);
+		} else if(erc) {
+			send_ldap_error(op, rs, erc,
+				"attempt to delete nonexistent attribute");
+			return(erc);
+		}
+	}
+
+/*
+** foreach Modification:
+**	if MOD_ADD or MOD_REPLACE, add Attribute;
+** if no Modifications were suitable:
+**	if config.strict, throw CONSTRAINT_VIOLATION;
+**	else, return early SUCCESS;
+** fabricate Entry with new Attribute chain;
+** glue_parent() for this Entry;
+** call bi_op_add() in local backend;
+**
+*/
+
+	Debug(LDAP_DEBUG_TRACE, "=> translucent_modify: fabricating local add\n", 0, 0, 0);
+	a = NULL;
+	for(del = 0, ax = NULL, m = op->orm_modlist; m; m = m->sml_next) {
+		if(((m->sml_op & LDAP_MOD_OP) != LDAP_MOD_ADD) &&
+		   ((m->sml_op & LDAP_MOD_OP) != LDAP_MOD_REPLACE)) {
+			Debug(LDAP_DEBUG_ANY,
+				"=> translucent_modify: silently dropped modification(%d): %s\n",
+				m->sml_op, m->sml_desc->ad_cname.bv_val, 0);
+			if((m->sml_op & LDAP_MOD_OP) == LDAP_MOD_DELETE) del++;
+			continue;
+		}
+		a = ch_calloc(1, sizeof(Attribute));
+		a->a_desc  = m->sml_desc;
+		a->a_vals  = m->sml_values;
+		a->a_nvals = m->sml_nvalues;
+		a->a_next  = ax;
+		ax = a;
+	}
+
+	if(del && ov->config->strict) {
+		free_attr_chain(a);
+		send_ldap_error(op, rs, LDAP_CONSTRAINT_VIOLATION,
+			"attempt to delete attributes from local database");
+		return(rs->sr_err);
+	}
+
+	if(!ax) {
+		if(ov->config->strict) {
+			send_ldap_error(op, rs, LDAP_CONSTRAINT_VIOLATION,
+				"modification contained other than ADD or REPLACE");
+			return(rs->sr_err);
+		}
+		op->o_bd->bd_info = (BackendInfo *) on;
+		/* rs->sr_text = "no valid modification found"; */
+		rs->sr_err = LDAP_SUCCESS;
+		send_ldap_result(op, rs);
+		return(rs->sr_err);
+	}
+
+	ne.e_id		= NOID;
+	ne.e_name	= op->o_req_dn;
+	ne.e_nname	= op->o_req_ndn;
+	ne.e_attrs	= a;
+	ne.e_ocflags	= 0;
+	ne.e_bv.bv_len	= 0;
+	ne.e_bv.bv_val	= NULL;
+	ne.e_private	= NULL;
+
+	nop.o_tag	= LDAP_REQ_ADD;
+	nop.oq_add.rs_e	= &ne;
+
+	op->o_bd->bd_info = (BackendInfo *) on;
+	glue_parent(&nop);
+
+	rc = on->on_info->oi_orig->bi_op_add(&nop, &nrs);
+	free_attr_chain(a);
+
+	return(rc);
+}
+
+static int translucent_compare(Operation *op, SlapReply *rs) {
+	slap_overinst *on = (slap_overinst *) op->o_bd->bd_info;
+	overlay_stack *ov = on->on_bi.bi_private;
+	void *private = op->o_bd->be_private;
+	translucent_configuration *cf = ov->config;
+
+	AttributeAssertion *ava = op->orc_ava;
+	Attribute *a, *an, *ra, *as = NULL;
+	Entry *e, *ee, *re;
+	int rc;
+
+	Debug(LDAP_DEBUG_TRACE, "==> translucent_compare: <%s> %s:%s\n",
+		op->o_req_dn.bv_val, ava->aa_desc->ad_cname.bv_val, ava->aa_value.bv_val);
+
+/*
+** if the local backend has an entry for this attribute:
+**	CONTINUE and let it do the compare;
+**
+*/
+
+	op->o_bd->bd_info = (BackendInfo *) on->on_info;
+	rc = be_entry_get_rw(op, &op->o_req_ndn, NULL, ava->aa_desc, 0, &e);
+	if(e && rc == LDAP_SUCCESS) {
+		be_entry_release_r(op, e);
+		op->o_bd->bd_info = (BackendInfo *) on;
+		return(SLAP_CB_CONTINUE);
+	}
+
+/*
+** call compare() in the captive backend;
+** return the result;
+**
+*/
+
+	op->o_bd->be_private = ov->private;
+	rc = ov->info->bi_op_compare(op, rs);
+	op->o_bd->be_private = private;
+	op->o_bd->bd_info = (BackendInfo *) on;
+	return(rc);
+}
+
+/*
+** translucent_search_cb()
+**	merge local data with the search result
+**
+*/
+
+static int translucent_search_cb(Operation *op, SlapReply *rs) {
+	slap_overinst *on;
+	Entry *e, *re = NULL;
+	Attribute *a, *ax, *an, *as = NULL;
+	BerVarray b, bx;
+	void *private;
+	int i, rc, size;
+
+	if(!op || !rs || rs->sr_type != REP_SEARCH || !rs->sr_entry)
+		return(SLAP_CB_CONTINUE);
+
+	Debug(LDAP_DEBUG_TRACE, "==> tranclucent_search_cb: %s\n",
+		rs->sr_entry->e_name.bv_val, 0, 0);
+
+	on = (slap_overinst *) op->o_bd->bd_info;
+	op->o_bd->bd_info = (BackendInfo *) on->on_info;
+
+	private = op->o_bd->be_private;
+	op->o_bd->be_private = op->o_callback->sc_private;
+
+	rc = be_entry_get_rw(op, &rs->sr_entry->e_nname, NULL, NULL, 0, &e);
+
+/*
+** if we got an entry from local backend:
+**	make a copy of this search result;
+**	foreach local attr:
+**		foreach search result attr:
+**			if match, result attr with local attr;
+**			if new local, add to list;
+**	append new local attrs to search result;
+**
+*/
+
+	if(e && rc == LDAP_SUCCESS) {
+		re = entry_dup(rs->sr_entry);
+		for(ax = e->e_attrs; ax; ax = ax->a_next) {
+#if 0
+			if(is_at_operational(ax->a_desc->ad_type)) continue;
+#endif
+			for(a = re->e_attrs; a; a = a->a_next) {
+				if(a->a_desc == ax->a_desc) {
+					if(a->a_vals != a->a_nvals)
+						ber_bvarray_free(a->a_nvals);
+					ber_bvarray_free(a->a_vals);
+					a->a_vals = dup_bervarray(ax->a_vals);
+					a->a_nvals = (ax->a_vals == ax->a_nvals) ?
+						a->a_vals : dup_bervarray(ax->a_nvals);
+					break;
+				}
+			}
+			if(a) continue;
+			an = attr_dup(ax);
+			an->a_next = as;
+			as = an;
+		}
+		be_entry_release_r(op, e);
+
+		/* literally append, so locals are always last */
+		if(as) {
+			if(re->e_attrs) {
+				for(ax = re->e_attrs; ax->a_next; ax = ax->a_next);
+				ax->a_next = as;
+			} else {
+				re->e_attrs = as;
+			}
+		}
+		rs->sr_entry = re;
+		rs->sr_flags |= REP_ENTRY_MUSTBEFREED;
+	}
+
+	op->o_bd->be_private = private;
+	op->o_bd->bd_info = (BackendInfo *) on;
+
+	return(SLAP_CB_CONTINUE);
+}
+
+/*
+** translucent_search()
+**	search via captive backend;
+**	override results with any local data;
+**
+*/
+
+static int translucent_search(Operation *op, SlapReply *rs) {
+	Operation nop = *op;
+
+	slap_overinst *on = (slap_overinst *) op->o_bd->bd_info;
+	slap_callback cb = { NULL, NULL, NULL, NULL };
+	overlay_stack *ov = on->on_bi.bi_private;
+	translucent_configuration *cf = ov->config;
+	void *private = op->o_bd->be_private;
+	int rc;
+
+	Debug(LDAP_DEBUG_TRACE, "==> translucent_search: <%s> %s\n",
+		op->o_req_dn.bv_val, op->ors_filterstr.bv_val, 0);
+	cb.sc_response = (slap_response *) translucent_search_cb;
+	cb.sc_private = private;
+
+	cb.sc_next = nop.o_callback;
+	nop.o_callback = &cb;
+
+	op->o_bd->be_private = ov->private;
+	rc = ov->info->bi_op_search(&nop, rs);
+	op->o_bd->be_private = private;
+
+	return(rs->sr_err);
+}
+
+
+/*
+** translucent_bind()
+**	pass bind request to captive backend;
+**
+*/
+
+static int translucent_bind(Operation *op, SlapReply *rs) {
+	slap_overinst *on = (slap_overinst *) op->o_bd->bd_info;
+	overlay_stack *ov = on->on_bi.bi_private;
+	void *private = op->o_bd->be_private;
+	int rc = 0;
+
+	Debug(LDAP_DEBUG_TRACE, "translucent_bind: <%s> method %d\n",
+		op->o_req_dn.bv_val, op->orb_method, 0);
+
+	op->o_bd->be_private = ov->private;
+	rc = ov->info->bi_op_bind(op, rs);
+	op->o_bd->be_private = private;
+
+	return(rc);
+}
+
+/*
+** translucent_config()
+**	pass config directives to captive backend;
+**	parse unrecognized directives ourselves;
+**
+*/
+
+static int translucent_config(
+	BackendDB	*be,
+	const char	*fname,
+	int		lineno,
+	int		argc,
+	char		**argv
+)
+{
+	slap_overinst *on = (slap_overinst *) be->bd_info;
+	overlay_stack *ov = on->on_bi.bi_private;
+	void *private = be->be_private;
+	int rc;
+
+	/* "this should never happen" */
+	if(!ov->info) {
+		fprintf(stderr, "fatal: captive backend not initialized");
+		return(1);
+	}
+
+	be->be_private = ov->private;
+	rc = ov->info->bi_db_config ? ov->info->bi_db_config(be, fname, lineno, argc, argv) : 0;
+	be->be_private = private;
+
+	/* pass okay or error up, SLAP_CONF_UNKNOWN might be ours */
+	if(rc == 0 || rc == 1) return(rc);
+
+	rc = 0;
+	if(!strcasecmp(*argv, "translucent_strict")) {
+		ov->config->strict++;
+	} else if(!strcasecmp(*argv, "translucent_no_add")) {
+		ov->config->no_add++;
+	} else if(!strcasecmp(*argv, "translucent_no_glue")) {
+		ov->config->glue++;
+	} else if(!strcasecmp(*argv, "translucent_debug")) {
+		if(argc == 1) {
+			ov->config->debug = 0xFFFF;
+			rc = 0;
+		} else if(argc == 2) {
+			ov->config->debug = atoi(argv[1]);
+			rc = 0;
+		} else {
+			fprintf(stderr, "%s: line %d: too many arguments (%d) to debug\n",
+				fname, lineno, argc);
+			rc = 1;
+		}
+	} else {
+		fprintf(stderr, "%s: line %d: unknown keyword %s\n",
+			fname, lineno, *argv);
+		rc = SLAP_CONF_UNKNOWN;
+	}
+	return(rc);
+}
+
+/*
+** translucent_db_init()
+**	initialize the captive backend;
+**
+*/
+
+static int translucent_db_init(BackendDB *be) {
+	slap_overinst *on = (slap_overinst *) be->bd_info;
+	void *private = be->be_private;
+	overlay_stack *ov;
+	int rc;
+
+	Debug(LDAP_DEBUG_TRACE, "==> translucent_init\n", 0, 0, 0);
+
+	ov = ch_calloc(1, sizeof(overlay_stack));
+	ov->config = ch_calloc(1, sizeof(translucent_configuration));
+	ov->info = backend_info("ldap");
+
+	if(!ov->info) {
+		Debug(LDAP_DEBUG_ANY, "translucent: backend_info failed!\n", 0, 0, 0);
+		return(1);
+	}
+
+	/* forcibly disable schema checking on the local backend */
+	SLAP_DBFLAGS(be) |= SLAP_DBFLAG_NO_SCHEMA_CHECK;
+
+	be->be_private = NULL;
+	rc = ov->info->bi_db_init ? ov->info->bi_db_init(be) : 0;
+
+	if(rc) Debug(LDAP_DEBUG_TRACE,
+		"translucent: bi_db_init() returned error %d\n", rc, 0, 0);
+
+	ov->private = be->be_private;
+	be->be_private = private;
+	on->on_bi.bi_private = ov;
+	return(rc);
+}
+
+/*
+** translucent_open()
+**	if the captive backend has an open() method, call it;
+**
+*/
+
+static int translucent_open(BackendDB *be) {
+	slap_overinst *on = (slap_overinst *) be->bd_info;
+	overlay_stack *ov = on->on_bi.bi_private;
+	void *private = be->be_private;
+	int rc;
+
+	/* "should never happen" */
+	if(!ov->info) {
+		Debug(LDAP_DEBUG_ANY, "translucent_open() called with bad ov->info\n", 0, 0, 0);
+		return(LDAP_OTHER);
+	}
+
+	Debug(LDAP_DEBUG_TRACE, "translucent_open\n", 0, 0, 0);
+
+	be->be_private = ov->private;
+	rc = ov->info->bi_db_open ? ov->info->bi_db_open(be) : 0;
+	be->be_private = private;
+
+	if(rc) Debug(LDAP_DEBUG_TRACE,
+		"translucent: bi_db_open() returned error %d\n", rc, 0, 0);
+
+	return(rc);
+}
+
+/*
+** translucent_close()
+**	if the captive backend has a close() method, call it;
+**	free any config data;
+**
+*/
+
+static int translucent_close(BackendDB *be) {
+	slap_overinst *on = (slap_overinst *) be->bd_info;
+	overlay_stack *ov = on->on_bi.bi_private;
+	translucent_configuration *cf = ov->config;
+	void *private = be->be_private;
+	int rc;
+
+	be->be_private = ov->private;
+	rc = (ov->info && ov->info->bi_db_close) ? ov->info->bi_db_close(be) : 0;
+	be->be_private = private;
+	if(ov->config) ch_free(ov->config);
+	ch_free(ov);
+	return(rc);
+}
+
+/*
+** translucent_init()
+**	initialize the slap_overinst with our entry points;
+**
+*/
+
+int translucent_init() {
+
+	translucent.on_bi.bi_type	= "translucent";
+	translucent.on_bi.bi_db_init	= translucent_db_init;
+	translucent.on_bi.bi_db_config	= translucent_config;
+	translucent.on_bi.bi_db_open	= translucent_open;
+	translucent.on_bi.bi_db_close	= translucent_close;
+	translucent.on_bi.bi_op_bind	= translucent_bind;
+	translucent.on_bi.bi_op_add	= translucent_add;
+	translucent.on_bi.bi_op_modify	= translucent_modify;
+	translucent.on_bi.bi_op_modrdn	= translucent_modrdn;
+	translucent.on_bi.bi_op_delete	= translucent_delete;
+	translucent.on_bi.bi_op_search	= translucent_search;
+	translucent.on_bi.bi_op_compare	= translucent_compare;
+
+	return(overlay_register(&translucent));
+}
+
+#if SLAPD_OVER_TRANSLUCENT == SLAPD_MOD_DYNAMIC && defined(PIC)
+int init_module(int argc, char *argv[]) {
+	return translucent_init();
+}
+#endif
+
+#endif /* SLAPD_OVER_TRANSLUCENT */
+