]> git.sur5r.net Git - openldap/blobdiff - servers/slapd/backover.c
Preliminary checkin for new access_allowed() signature. Still need
[openldap] / servers / slapd / backover.c
index bda4c6cb03c6538ff8c21522780a0a9774666976..1c4f4e1a2346a26fe6df7af2001792ef9171278f 100644 (file)
@@ -2,7 +2,7 @@
 /* $OpenLDAP$ */
 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
  *
- * Copyright 2003-2005 The OpenLDAP Foundation.
+ * Copyright 2003-2009 The OpenLDAP Foundation.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
 
 static slap_overinst *overlays;
 
-enum db_which { db_open = 0, db_close, db_destroy };
-
-static int
-over_db_func(
-       BackendDB *be,
-       enum db_which which
-)
-{
-       slap_overinfo *oi = be->bd_info->bi_private;
-       slap_overinst *on = oi->oi_list;
-       BackendInfo *bi_orig = be->bd_info;
-       BI_db_open **func;
-       int rc = 0;
-
-       func = &oi->oi_orig->bi_db_open;
-       if ( func[which] ) {
-               be->bd_info = oi->oi_orig;
-               rc = func[which]( be );
-       }
-
-       for (; on && rc == 0; on=on->on_next) {
-               be->bd_info = &on->on_bi;
-               func = &on->on_bi.bi_db_open;
-               if (func[which]) {
-                       rc = func[which]( be );
-               }
-       }
-       be->bd_info = bi_orig;
-       return rc;
-}
-
 static int
 over_db_config(
        BackendDB *be,
@@ -72,12 +41,13 @@ over_db_config(
        slap_overinfo *oi = be->bd_info->bi_private;
        slap_overinst *on = oi->oi_list;
        BackendInfo *bi_orig = be->bd_info;
-       ConfigArgs ca;
-       ConfigTable *ct;
+       struct ConfigOCs *be_cf_ocs = be->be_cf_ocs;
+       ConfigArgs ca = {0};
        int rc = 0;
 
        if ( oi->oi_orig->bi_db_config ) {
                be->bd_info = oi->oi_orig;
+               be->be_cf_ocs = oi->oi_orig->bi_cf_ocs;
                rc = oi->oi_orig->bi_db_config( be, fname, lineno,
                        argc, argv );
 
@@ -131,6 +101,11 @@ over_db_config(
        ca.fname = fname;
        ca.lineno = lineno;
        ca.be = be;
+       snprintf( ca.log, sizeof( ca.log ), "%s: line %d",
+                       ca.fname, ca.lineno );
+       ca.op = SLAP_CONFIG_ADD;
+       ca.valx = -1;
+
        for (; on; on=on->on_next) {
                rc = SLAP_CONF_UNKNOWN;
                if (on->on_bi.bi_cf_ocs) {
@@ -138,7 +113,10 @@ over_db_config(
                        ca.bi = &on->on_bi;
                        ct = config_find_keyword( on->on_bi.bi_cf_ocs->co_table, &ca );
                        if ( ct ) {
+                               ca.table = on->on_bi.bi_cf_ocs->co_type;
                                rc = config_add_vals( ct, &ca );
+                               if ( rc != SLAP_CONF_UNKNOWN )
+                                       break;
                        }
                }
                if (on->on_bi.bi_db_config && rc == SLAP_CONF_UNKNOWN) {
@@ -149,20 +127,42 @@ over_db_config(
                }
        }
        be->bd_info = bi_orig;
+       be->be_cf_ocs = be_cf_ocs;
+       
        return rc;
 }
 
 static int
 over_db_open(
-       BackendDB *be
+       BackendDB *be,
+       ConfigReply *cr
 )
 {
-       return over_db_func( be, db_open );
+       slap_overinfo *oi = be->bd_info->bi_private;
+       slap_overinst *on = oi->oi_list;
+       BackendDB db = *be;
+       int rc = 0;
+
+       db.be_flags |= SLAP_DBFLAG_OVERLAY;
+       db.bd_info = oi->oi_orig;
+       if ( db.bd_info->bi_db_open ) {
+               rc = db.bd_info->bi_db_open( &db, cr );
+       }
+
+       for (; on && rc == 0; on=on->on_next) {
+               db.bd_info = &on->on_bi;
+               if ( db.bd_info->bi_db_open ) {
+                       rc = db.bd_info->bi_db_open( &db, cr );
+               }
+       }
+
+       return rc;
 }
 
 static int
 over_db_close(
-       BackendDB *be
+       BackendDB *be,
+       ConfigReply *cr
 )
 {
        slap_overinfo *oi = be->bd_info->bi_private;
@@ -173,13 +173,13 @@ over_db_close(
        for (; on && rc == 0; on=on->on_next) {
                be->bd_info = &on->on_bi;
                if ( be->bd_info->bi_db_close ) {
-                       rc = be->bd_info->bi_db_close( be );
+                       rc = be->bd_info->bi_db_close( be, cr );
                }
        }
 
        if ( oi->oi_orig->bi_db_close ) {
                be->bd_info = oi->oi_orig;
-               rc = be->bd_info->bi_db_close( be );
+               rc = be->bd_info->bi_db_close( be, cr );
        }
 
        be->bd_info = bi_orig;
@@ -188,19 +188,35 @@ over_db_close(
 
 static int
 over_db_destroy(
-       BackendDB *be
+       BackendDB *be,
+       ConfigReply *cr
 )
 {
        slap_overinfo *oi = be->bd_info->bi_private;
        slap_overinst *on = oi->oi_list, *next;
-       int rc;
+       BackendInfo *bi_orig = be->bd_info;
+       int rc = 0;
 
-       rc = over_db_func( be, db_destroy );
+       be->bd_info = oi->oi_orig;
+       if ( be->bd_info->bi_db_destroy ) {
+               rc = be->bd_info->bi_db_destroy( be, cr );
+       }
 
-       for (next = on->on_next; on; on=next) {
-               next = on->on_next;
-               free( on );
+       for (; on && rc == 0; on=on->on_next) {
+               be->bd_info = &on->on_bi;
+               if ( be->bd_info->bi_db_destroy ) {
+                       rc = be->bd_info->bi_db_destroy( be, cr );
+               }
        }
+
+       on = oi->oi_list;
+       if ( on ) {
+               for (next = on->on_next; on; on=next) {
+                       next = on->on_next;
+                       free( on );
+               }
+       }
+       be->bd_info = bi_orig;
        free( oi );
        return rc;
 }
@@ -222,63 +238,23 @@ over_back_response ( Operation *op, SlapReply *rs )
                        if ( rc != SLAP_CB_CONTINUE ) break;
                }
        }
+       /* Bypass the remaining on_response layers, but allow
+        * normal execution to continue.
+        */
+       if ( rc == SLAP_CB_BYPASS )
+               rc = SLAP_CB_CONTINUE;
        op->o_bd = be;
        return rc;
 }
 
-enum op_which {
-       op_bind = 0,
-       op_unbind,
-       op_search,
-       op_compare,
-       op_modify,
-       op_modrdn,
-       op_add,
-       op_delete,
-       op_abandon,
-       op_cancel,
-       op_extended,
-       op_aux_operational,
-       op_aux_chk_referrals,
-       op_aux_chk_controls,
-       op_last
-};
-
-/*
- * default return code in case of missing backend function
- * and overlay stack returning SLAP_CB_CONTINUE
- */
-static int op_rc[] = {
-       LDAP_UNWILLING_TO_PERFORM,      /* bind */
-       LDAP_UNWILLING_TO_PERFORM,      /* unbind */
-       LDAP_UNWILLING_TO_PERFORM,      /* search */
-       SLAP_CB_CONTINUE,               /* compare; pass to frontend */
-       LDAP_UNWILLING_TO_PERFORM,      /* modify */
-       LDAP_UNWILLING_TO_PERFORM,      /* modrdn */
-       LDAP_UNWILLING_TO_PERFORM,      /* add */
-       LDAP_UNWILLING_TO_PERFORM,      /* delete */
-       LDAP_UNWILLING_TO_PERFORM,      /* abandon */
-       LDAP_UNWILLING_TO_PERFORM,      /* cancel */
-       LDAP_UNWILLING_TO_PERFORM,      /* extended */
-       LDAP_SUCCESS,                   /* aux_operational */
-       LDAP_SUCCESS,                   /* aux_chk_referrals */
-       SLAP_CB_CONTINUE                /* aux_chk_controls; pass to frontend */
-};
-
-#ifdef SLAP_OVERLAY_ACCESS
 static int
 over_access_allowed(
        Operation               *op,
-       Entry                   *e,
-       AttributeDescription    *desc,
-       struct berval           *val,
-       slap_access_t           access,
-       AccessControlState      *state,
-       slap_mask_t             *maskp )
+       AclCheck                *ak )
 {
        slap_overinfo *oi;
        slap_overinst *on;
-       BackendInfo *bi = op->o_bd->bd_info;
+       BackendInfo *bi;
        BackendDB *be = op->o_bd, db;
        int rc = SLAP_CB_CONTINUE;
 
@@ -286,7 +262,13 @@ over_access_allowed(
         * when global overlays are used... */
        assert( op->o_bd != NULL );
 
-       oi = op->o_bd->bd_info->bi_private;
+       bi = op->o_bd->bd_info;
+       /* Were we invoked on the frontend? */
+       if ( !bi->bi_access_allowed ) {
+               oi = frontendDB->bd_info->bi_private;
+       } else {
+               oi = op->o_bd->bd_info->bi_private;
+       }
        on = oi->oi_list;
 
        for ( ; on; on = on->on_next ) {
@@ -299,8 +281,7 @@ over_access_allowed(
                        }
 
                        op->o_bd->bd_info = (BackendInfo *)on;
-                       rc = on->on_bi.bi_access_allowed( op, e,
-                               desc, val, access, state, maskp );
+                       rc = on->on_bi.bi_access_allowed( op, ak );
                        if ( rc != SLAP_CB_CONTINUE ) break;
                }
        }
@@ -320,8 +301,7 @@ over_access_allowed(
                        bi_access_allowed = slap_access_allowed;
                }
 
-               rc = bi_access_allowed( op, e,
-                       desc, val, access, state, maskp );
+               rc = bi_access_allowed( op, ak );
        }
        /* should not fall thru this far without anything happening... */
        if ( rc == SLAP_CB_CONTINUE ) {
@@ -334,20 +314,161 @@ over_access_allowed(
 
        return rc;
 }
-#endif /* SLAP_OVERLAY_ACCESS */
+
+int
+overlay_entry_get_ov(
+       Operation               *op,
+       struct berval   *dn,
+       ObjectClass             *oc,
+       AttributeDescription    *ad,
+       int     rw,
+       Entry   **e,
+       slap_overinst *on )
+{
+       slap_overinfo *oi = on->on_info;
+       BackendDB *be = op->o_bd, db;
+       BackendInfo *bi = op->o_bd->bd_info;
+       int rc = SLAP_CB_CONTINUE;
+
+       for ( ; on; on = on->on_next ) {
+               if ( on->on_bi.bi_entry_get_rw ) {
+                       /* NOTE: do not copy the structure until required */
+                       if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
+                               db = *op->o_bd;
+                               db.be_flags |= SLAP_DBFLAG_OVERLAY;
+                               op->o_bd = &db;
+                       }
+
+                       op->o_bd->bd_info = (BackendInfo *)on;
+                       rc = on->on_bi.bi_entry_get_rw( op, dn,
+                               oc, ad, rw, e );
+                       if ( rc != SLAP_CB_CONTINUE ) break;
+               }
+       }
+
+       if ( rc == SLAP_CB_CONTINUE ) {
+               /* if the database structure was changed, o_bd points to a
+                * copy of the structure; put the original bd_info in place */
+               if ( SLAP_ISOVERLAY( op->o_bd ) ) {
+                       op->o_bd->bd_info = oi->oi_orig;
+               }
+
+               if ( oi->oi_orig->bi_entry_get_rw ) {
+                       rc = oi->oi_orig->bi_entry_get_rw( op, dn,
+                               oc, ad, rw, e );
+               }
+       }
+       /* should not fall thru this far without anything happening... */
+       if ( rc == SLAP_CB_CONTINUE ) {
+               rc = LDAP_UNWILLING_TO_PERFORM;
+       }
+
+       op->o_bd = be;
+       op->o_bd->bd_info = bi;
+
+       return rc;
+}
+
+static int
+over_entry_get_rw(
+       Operation               *op,
+       struct berval   *dn,
+       ObjectClass             *oc,
+       AttributeDescription    *ad,
+       int     rw,
+       Entry   **e )
+{
+       slap_overinfo *oi;
+       slap_overinst *on;
+
+       assert( op->o_bd != NULL );
+
+       oi = op->o_bd->bd_info->bi_private;
+       on = oi->oi_list;
+
+       return overlay_entry_get_ov( op, dn, oc, ad, rw, e, on );
+}
+
+int
+overlay_entry_release_ov(
+       Operation       *op,
+       Entry   *e,
+       int rw,
+       slap_overinst *on )
+{
+       slap_overinfo *oi = on->on_info;
+       BackendDB *be = op->o_bd, db;
+       BackendInfo *bi = op->o_bd->bd_info;
+       int rc = SLAP_CB_CONTINUE;
+
+       for ( ; on; on = on->on_next ) {
+               if ( on->on_bi.bi_entry_release_rw ) {
+                       /* NOTE: do not copy the structure until required */
+                       if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
+                               db = *op->o_bd;
+                               db.be_flags |= SLAP_DBFLAG_OVERLAY;
+                               op->o_bd = &db;
+                       }
+
+                       op->o_bd->bd_info = (BackendInfo *)on;
+                       rc = on->on_bi.bi_entry_release_rw( op, e, rw );
+                       if ( rc != SLAP_CB_CONTINUE ) break;
+               }
+       }
+
+       if ( rc == SLAP_CB_CONTINUE ) {
+               /* if the database structure was changed, o_bd points to a
+                * copy of the structure; put the original bd_info in place */
+               if ( SLAP_ISOVERLAY( op->o_bd ) ) {
+                       op->o_bd->bd_info = oi->oi_orig;
+               }
+
+               if ( oi->oi_orig->bi_entry_release_rw ) {
+                       rc = oi->oi_orig->bi_entry_release_rw( op, e, rw );
+               }
+       }
+       /* should not fall thru this far without anything happening... */
+       if ( rc == SLAP_CB_CONTINUE ) {
+               entry_free( e );
+               rc = 0;
+       }
+
+       op->o_bd = be;
+       op->o_bd->bd_info = bi;
+
+       return rc;
+}
 
 static int
-over_op_func(
-       Operation *op,
-       SlapReply *rs,
-       enum op_which which
-)
+over_entry_release_rw(
+       Operation       *op,
+       Entry   *e,
+       int rw )
 {
        slap_overinfo *oi;
        slap_overinst *on;
-       BI_op_bind **func;
+
+       assert( op->o_bd != NULL );
+
+       oi = op->o_bd->bd_info->bi_private;
+       on = oi->oi_list;
+
+       return overlay_entry_release_ov( op, e, rw, on );
+}
+
+static int
+over_acl_group(
+       Operation               *op,
+       Entry                   *e,
+       struct berval           *gr_ndn,
+       struct berval           *op_ndn,
+       ObjectClass             *group_oc,
+       AttributeDescription    *group_at )
+{
+       slap_overinfo *oi;
+       slap_overinst *on;
+       BackendInfo *bi = op->o_bd->bd_info;
        BackendDB *be = op->o_bd, db;
-       slap_callback cb = {NULL, over_back_response, NULL, NULL};
        int rc = SLAP_CB_CONTINUE;
 
        /* FIXME: used to happen for instance during abandon
@@ -357,14 +478,172 @@ over_op_func(
        oi = op->o_bd->bd_info->bi_private;
        on = oi->oi_list;
 
-       if ( !SLAP_ISOVERLAY( op->o_bd )) {
-               db = *op->o_bd;
-               db.be_flags |= SLAP_DBFLAG_OVERLAY;
-               op->o_bd = &db;
+       for ( ; on; on = on->on_next ) {
+               if ( on->on_bi.bi_acl_group ) {
+                       /* NOTE: do not copy the structure until required */
+                       if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
+                               db = *op->o_bd;
+                               db.be_flags |= SLAP_DBFLAG_OVERLAY;
+                               op->o_bd = &db;
+                       }
+
+                       op->o_bd->bd_info = (BackendInfo *)on;
+                       rc = on->on_bi.bi_acl_group( op, e,
+                               gr_ndn, op_ndn, group_oc, group_at );
+                       if ( rc != SLAP_CB_CONTINUE ) break;
+               }
        }
-       cb.sc_next = op->o_callback;
-       cb.sc_private = oi;
-       op->o_callback = &cb;
+
+       if ( rc == SLAP_CB_CONTINUE ) {
+               BI_acl_group            *bi_acl_group;
+
+               /* if the database structure was changed, o_bd points to a
+                * copy of the structure; put the original bd_info in place */
+               if ( SLAP_ISOVERLAY( op->o_bd ) ) {
+                       op->o_bd->bd_info = oi->oi_orig;
+               }
+
+               if ( oi->oi_orig->bi_acl_group ) {
+                       bi_acl_group = oi->oi_orig->bi_acl_group;
+               } else {
+                       bi_acl_group = backend_group;
+               }
+
+               rc = bi_acl_group( op, e,
+                       gr_ndn, op_ndn, group_oc, group_at );
+       }
+       /* should not fall thru this far without anything happening... */
+       if ( rc == SLAP_CB_CONTINUE ) {
+               /* access not allowed */
+               rc = 0;
+       }
+
+       op->o_bd = be;
+       op->o_bd->bd_info = bi;
+
+       return rc;
+}
+
+static int
+over_acl_attribute(
+       Operation               *op,
+       Entry                   *target,
+       struct berval           *entry_ndn,
+       AttributeDescription    *entry_at,
+       BerVarray               *vals,
+       slap_access_t           access )
+{
+       slap_overinfo *oi;
+       slap_overinst *on;
+       BackendInfo *bi = op->o_bd->bd_info;
+       BackendDB *be = op->o_bd, db;
+       int rc = SLAP_CB_CONTINUE;
+
+       /* FIXME: used to happen for instance during abandon
+        * when global overlays are used... */
+       assert( op->o_bd != NULL );
+
+       oi = op->o_bd->bd_info->bi_private;
+       on = oi->oi_list;
+
+       for ( ; on; on = on->on_next ) {
+               if ( on->on_bi.bi_acl_attribute ) {
+                       /* NOTE: do not copy the structure until required */
+                       if ( !SLAP_ISOVERLAY( op->o_bd ) ) {
+                               db = *op->o_bd;
+                               db.be_flags |= SLAP_DBFLAG_OVERLAY;
+                               op->o_bd = &db;
+                       }
+
+                       op->o_bd->bd_info = (BackendInfo *)on;
+                       rc = on->on_bi.bi_acl_attribute( op, target,
+                               entry_ndn, entry_at, vals, access );
+                       if ( rc != SLAP_CB_CONTINUE ) break;
+               }
+       }
+
+       if ( rc == SLAP_CB_CONTINUE ) {
+               BI_acl_attribute                *bi_acl_attribute;
+
+               /* if the database structure was changed, o_bd points to a
+                * copy of the structure; put the original bd_info in place */
+               if ( SLAP_ISOVERLAY( op->o_bd ) ) {
+                       op->o_bd->bd_info = oi->oi_orig;
+               }
+
+               if ( oi->oi_orig->bi_acl_attribute ) {
+                       bi_acl_attribute = oi->oi_orig->bi_acl_attribute;
+               } else {
+                       bi_acl_attribute = backend_attribute;
+               }
+
+               rc = bi_acl_attribute( op, target,
+                       entry_ndn, entry_at, vals, access );
+       }
+       /* should not fall thru this far without anything happening... */
+       if ( rc == SLAP_CB_CONTINUE ) {
+               /* access not allowed */
+               rc = 0;
+       }
+
+       op->o_bd = be;
+       op->o_bd->bd_info = bi;
+
+       return rc;
+}
+
+int
+overlay_callback_after_backover( Operation *op, slap_callback *sc, int append )
+{
+       slap_callback **scp;
+
+       for ( scp = &op->o_callback; *scp != NULL; scp = &(*scp)->sc_next ) {
+               if ( (*scp)->sc_response == over_back_response ) {
+                       sc->sc_next = (*scp)->sc_next;
+                       (*scp)->sc_next = sc;
+                       return 0;
+               }
+       }
+
+       if ( append ) {
+               *scp = sc;
+               return 0;
+       }
+
+       return 1;
+}
+
+/*
+ * default return code in case of missing backend function
+ * and overlay stack returning SLAP_CB_CONTINUE
+ */
+static int op_rc[ op_last ] = {
+       LDAP_UNWILLING_TO_PERFORM,      /* bind */
+       LDAP_UNWILLING_TO_PERFORM,      /* unbind */
+       LDAP_UNWILLING_TO_PERFORM,      /* search */
+       SLAP_CB_CONTINUE,               /* compare; pass to frontend */
+       LDAP_UNWILLING_TO_PERFORM,      /* modify */
+       LDAP_UNWILLING_TO_PERFORM,      /* modrdn */
+       LDAP_UNWILLING_TO_PERFORM,      /* add */
+       LDAP_UNWILLING_TO_PERFORM,      /* delete */
+       LDAP_UNWILLING_TO_PERFORM,      /* abandon */
+       LDAP_UNWILLING_TO_PERFORM,      /* cancel */
+       LDAP_UNWILLING_TO_PERFORM,      /* extended */
+       LDAP_SUCCESS,                   /* aux_operational */
+       LDAP_SUCCESS,                   /* aux_chk_referrals */
+       SLAP_CB_CONTINUE                /* aux_chk_controls; pass to frontend */
+};
+
+int overlay_op_walk(
+       Operation *op,
+       SlapReply *rs,
+       slap_operation_t which,
+       slap_overinfo *oi,
+       slap_overinst *on
+)
+{
+       BI_op_bind **func;
+       int rc = SLAP_CB_CONTINUE;
 
        for (; on; on=on->on_next ) {
                func = &on->on_bi.bi_op_bind;
@@ -374,6 +653,8 @@ over_op_func(
                        if ( rc != SLAP_CB_CONTINUE ) break;
                }
        }
+       if ( rc == SLAP_CB_BYPASS )
+               rc = SLAP_CB_CONTINUE;
 
        func = &oi->oi_orig->bi_op_bind;
        if ( func[which] && rc == SLAP_CB_CONTINUE ) {
@@ -390,16 +671,55 @@ over_op_func(
         */
        if ( rc == LDAP_UNWILLING_TO_PERFORM ) {
                slap_callback *sc_next;
-               for ( ; op->o_callback && op->o_callback != cb.sc_next; 
-                       op->o_callback = sc_next ) {
+               for ( ; op->o_callback && op->o_callback->sc_response !=
+                       over_back_response; op->o_callback = sc_next ) {
                        sc_next = op->o_callback->sc_next;
                        if ( op->o_callback->sc_cleanup ) {
                                op->o_callback->sc_cleanup( op, rs );
                        }
                }
        }
+       return rc;
+}
+
+static int
+over_op_func(
+       Operation *op,
+       SlapReply *rs,
+       slap_operation_t which
+)
+{
+       slap_overinfo *oi;
+       slap_overinst *on;
+       BackendDB *be = op->o_bd, db;
+       slap_callback cb = {NULL, over_back_response, NULL, NULL}, **sc;
+       int rc = SLAP_CB_CONTINUE;
+
+       /* FIXME: used to happen for instance during abandon
+        * when global overlays are used... */
+       assert( op->o_bd != NULL );
+
+       oi = op->o_bd->bd_info->bi_private;
+       on = oi->oi_list;
+
+       if ( !SLAP_ISOVERLAY( op->o_bd )) {
+               db = *op->o_bd;
+               db.be_flags |= SLAP_DBFLAG_OVERLAY;
+               op->o_bd = &db;
+       }
+       cb.sc_next = op->o_callback;
+       cb.sc_private = oi;
+       op->o_callback = &cb;
+
+       rc = overlay_op_walk( op, rs, which, oi, on );
+       for ( sc = &op->o_callback; *sc; sc = &(*sc)->sc_next ) {
+               if ( *sc == &cb ) {
+                       *sc = cb.sc_next;
+                       break;
+               }
+       }
+
        op->o_bd = be;
-       op->o_callback = cb.sc_next;
        return rc;
 }
 
@@ -487,16 +807,24 @@ over_aux_chk_controls( Operation *op, SlapReply *rs )
        return over_op_func( op, rs, op_aux_chk_controls );
 }
 
+enum conn_which {
+       conn_init = 0,
+       conn_destroy,
+       conn_last
+};
+
 static int
-over_connection_destroy(
+over_connection_func(
        BackendDB       *bd,
-       Connection      *conn
+       Connection      *conn,
+       enum conn_which which
 )
 {
-       slap_overinfo *oi;
-       slap_overinst *on;
-       BackendDB db;
-       int rc = SLAP_CB_CONTINUE;
+       slap_overinfo           *oi;
+       slap_overinst           *on;
+       BackendDB               db;
+       int                     rc = SLAP_CB_CONTINUE;
+       BI_connection_init      **func;
 
        /* FIXME: used to happen for instance during abandon
         * when global overlays are used... */
@@ -505,23 +833,25 @@ over_connection_destroy(
        oi = bd->bd_info->bi_private;
        on = oi->oi_list;
 
-       if ( !SLAP_ISOVERLAY( bd )) {
+       if ( !SLAP_ISOVERLAY( bd ) ) {
                db = *bd;
                db.be_flags |= SLAP_DBFLAG_OVERLAY;
                bd = &db;
        }
 
-       for (; on; on=on->on_next ) {
-               if ( on->on_bi.bi_connection_destroy ) {
+       for ( ; on; on = on->on_next ) {
+               func = &on->on_bi.bi_connection_init;
+               if ( func[ which ] ) {
                        bd->bd_info = (BackendInfo *)on;
-                       rc = on->on_bi.bi_connection_destroy( bd, conn );
+                       rc = func[ which ]( bd, conn );
                        if ( rc != SLAP_CB_CONTINUE ) break;
                }
        }
 
-       if ( oi->oi_orig->bi_connection_destroy && rc == SLAP_CB_CONTINUE ) {
+       func = &oi->oi_orig->bi_connection_init;
+       if ( func[ which ] && rc == SLAP_CB_CONTINUE ) {
                bd->bd_info = oi->oi_orig;
-               rc = oi->oi_orig->bi_connection_destroy( bd, conn );
+               rc = func[ which ]( bd, conn );
        }
        /* should not fall thru this far without anything happening... */
        if ( rc == SLAP_CB_CONTINUE ) {
@@ -531,11 +861,92 @@ over_connection_destroy(
        return rc;
 }
 
+static int
+over_connection_init(
+       BackendDB       *bd,
+       Connection      *conn
+)
+{
+       return over_connection_func( bd, conn, conn_init );
+}
+
+static int
+over_connection_destroy(
+       BackendDB       *bd,
+       Connection      *conn
+)
+{
+       return over_connection_func( bd, conn, conn_destroy );
+}
+
 int
 overlay_register(
        slap_overinst *on
 )
 {
+       slap_overinst   *tmp;
+
+       /* FIXME: check for duplicates? */
+       for ( tmp = overlays; tmp != NULL; tmp = tmp->on_next ) {
+               if ( strcmp( on->on_bi.bi_type, tmp->on_bi.bi_type ) == 0 ) {
+                       Debug( LDAP_DEBUG_ANY,
+                               "overlay_register(\"%s\"): "
+                               "name already in use.\n",
+                               on->on_bi.bi_type, 0, 0 );
+                       return -1;
+               }
+
+               if ( on->on_bi.bi_obsolete_names != NULL ) {
+                       int     i;
+
+                       for ( i = 0; on->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
+                               if ( strcmp( on->on_bi.bi_obsolete_names[ i ], tmp->on_bi.bi_type ) == 0 ) {
+                                       Debug( LDAP_DEBUG_ANY,
+                                               "overlay_register(\"%s\"): "
+                                               "obsolete name \"%s\" already in use "
+                                               "by overlay \"%s\".\n",
+                                               on->on_bi.bi_type,
+                                               on->on_bi.bi_obsolete_names[ i ],
+                                               tmp->on_bi.bi_type );
+                                       return -1;
+                               }
+                       }
+               }
+
+               if ( tmp->on_bi.bi_obsolete_names != NULL ) {
+                       int     i;
+
+                       for ( i = 0; tmp->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
+                               int     j;
+
+                               if ( strcmp( on->on_bi.bi_type, tmp->on_bi.bi_obsolete_names[ i ] ) == 0 ) {
+                                       Debug( LDAP_DEBUG_ANY,
+                                               "overlay_register(\"%s\"): "
+                                               "name already in use "
+                                               "as obsolete by overlay \"%s\".\n",
+                                               on->on_bi.bi_type,
+                                               tmp->on_bi.bi_obsolete_names[ i ], 0 );
+                                       return -1;
+                               }
+
+                               if ( on->on_bi.bi_obsolete_names != NULL ) {
+                                       for ( j = 0; on->on_bi.bi_obsolete_names[ j ] != NULL; j++ ) {
+                                               if ( strcmp( on->on_bi.bi_obsolete_names[ j ], tmp->on_bi.bi_obsolete_names[ i ] ) == 0 ) {
+                                                       Debug( LDAP_DEBUG_ANY,
+                                                               "overlay_register(\"%s\"): "
+                                                               "obsolete name \"%s\" already in use "
+                                                               "as obsolete by overlay \"%s\".\n",
+                                                               on->on_bi.bi_type,
+                                                               on->on_bi.bi_obsolete_names[ j ],
+                                                               tmp->on_bi.bi_type );
+                                                       return -1;
+                                               }
+                                       }
+                               }
+                       }
+               }
+       }
+
        on->on_next = overlays;
        overlays = on;
        return 0;
@@ -543,8 +954,8 @@ overlay_register(
 
 /*
  * iterator on registered overlays; overlay_next( NULL ) returns the first
- * overlay; subsequent calls with the previously returned value allow to 
- * iterate over the entire list; returns NULL when no more overlays are 
+ * overlay; subsequent calls with the previously returned value allow to 
+ * iterate over the entire list; returns NULL when no more overlays are 
  * registered.
  */
 
@@ -570,14 +981,30 @@ overlay_find( const char *over_type )
 {
        slap_overinst *on = overlays;
 
-       assert( over_type );
+       assert( over_type != NULL );
 
        for ( ; on; on = on->on_next ) {
                if ( strcmp( on->on_bi.bi_type, over_type ) == 0 ) {
-                       break;
+                       goto foundit;
+               }
+
+               if ( on->on_bi.bi_obsolete_names != NULL ) {
+                       int     i;
+
+                       for ( i = 0; on->on_bi.bi_obsolete_names[ i ] != NULL; i++ ) {
+                               if ( strcmp( on->on_bi.bi_obsolete_names[ i ], over_type ) == 0 ) {
+                                       Debug( LDAP_DEBUG_ANY,
+                                               "overlay_find(\"%s\"): "
+                                               "obsolete name for \"%s\".\n",
+                                               on->on_bi.bi_obsolete_names[ i ],
+                                               on->on_bi.bi_type, 0 );
+                                       goto foundit;
+                               }
+                       }
                }
        }
 
+foundit:;
        return on;
 }
 
@@ -605,7 +1032,7 @@ overlay_is_inst( BackendDB *be, const char *over_type )
 {
        slap_overinst   *on;
 
-       assert( be );
+       assert( be != NULL );
 
        if ( !overlay_is_over( be ) ) {
                return 0;
@@ -624,7 +1051,6 @@ overlay_is_inst( BackendDB *be, const char *over_type )
 int
 overlay_register_control( BackendDB *be, const char *oid )
 {
-       int             rc = 0;
        int             gotit = 0;
        int             cid;
 
@@ -632,12 +1058,12 @@ overlay_register_control( BackendDB *be, const char *oid )
                return -1;
        }
 
-       if ( SLAP_DBFLAGS( be ) & SLAP_DBFLAG_GLOBAL_OVERLAY ) {
+       if ( SLAP_ISGLOBALOVERLAY( be ) ) {
                BackendDB *bd;
                
                /* add to all backends... */
                LDAP_STAILQ_FOREACH( bd, &backendDB, be_next ) {
-                       if ( be == bd ) {
+                       if ( bd == be->bd_self ) {
                                gotit = 1;
                        }
 
@@ -647,22 +1073,144 @@ overlay_register_control( BackendDB *be, const char *oid )
 
        }
        
-       if ( rc == 0 && !gotit ) {
-               be->be_ctrls[ cid ] = 1;
-               be->be_ctrls[ SLAP_MAX_CIDS ] = 1;
+       if ( !gotit ) {
+               be->bd_self->be_ctrls[ cid ] = 1;
+               be->bd_self->be_ctrls[ SLAP_MAX_CIDS ] = 1;
        }
 
-       return rc;
+       return 0;
+}
+
+void
+overlay_destroy_one( BackendDB *be, slap_overinst *on )
+{
+       slap_overinfo *oi = on->on_info;
+       slap_overinst **oidx;
+
+       for ( oidx = &oi->oi_list; *oidx; oidx = &(*oidx)->on_next ) {
+               if ( *oidx == on ) {
+                       *oidx = on->on_next;
+                       if ( on->on_bi.bi_db_destroy ) {
+                               BackendInfo *bi_orig = be->bd_info;
+                               be->bd_info = (BackendInfo *)on;
+                               on->on_bi.bi_db_destroy( be, NULL );
+                               be->bd_info = bi_orig;
+                       }
+                       free( on );
+                       break;
+               }
+       }
+}
+
+#ifdef SLAP_CONFIG_DELETE
+void
+overlay_remove( BackendDB *be, slap_overinst *on )
+{
+       slap_overinfo *oi = on->on_info;
+       slap_overinst **oidx;
+       BackendInfo *bi_orig;
+
+       /* remove overlay from oi_list an call db_close and db_destroy
+        * handlers */
+       for ( oidx = &oi->oi_list; *oidx; oidx = &(*oidx)->on_next ) {
+               if ( *oidx == on ) {
+                       *oidx = on->on_next;
+                       bi_orig = be->bd_info;
+                       be->bd_info = (BackendInfo *)on;
+                       if ( on->on_bi.bi_db_close ) {
+                               on->on_bi.bi_db_close( be, NULL );
+                       }
+                       if ( on->on_bi.bi_db_destroy ) {
+                               on->on_bi.bi_db_destroy( be, NULL );
+                       }
+                       be->bd_info = bi_orig;
+                       free( on );
+                       break;
+               }
+       }
+       
+       /* clean up after removing last overlay */
+       if ( ! oi->oi_list ) 
+       {
+               /* reset db flags and bd_info to orig */
+               SLAP_DBFLAGS( be ) &= ~SLAP_DBFLAG_GLOBAL_OVERLAY;
+               be->bd_info = oi->oi_orig;
+               ch_free(oi);
+       }
+}
+#endif /* SLAP_CONFIG_DELETE */
+
+void
+overlay_insert( BackendDB *be, slap_overinst *on2, slap_overinst ***prev,
+       int idx )
+{
+       slap_overinfo *oi = (slap_overinfo *)be->bd_info;
+
+       if ( idx == -1 ) {
+               on2->on_next = oi->oi_list;
+               oi->oi_list = on2;
+       } else {
+               int i;
+               slap_overinst *on, *otmp1 = NULL, *otmp2;
+
+               /* Since the list is in reverse order and is singly linked,
+                * we reverse it to find the idx insertion point. Adding
+                * on overlay at a specific point should be a pretty
+                * infrequent occurrence.
+                */
+               for ( on = oi->oi_list; on; on=otmp2 ) {
+                       otmp2 = on->on_next;
+                       on->on_next = otmp1;
+                       otmp1 = on;
+               }
+               oi->oi_list = NULL;
+               /* advance to insertion point */
+               for ( i=0, on = otmp1; i<idx; i++ ) {
+                       otmp1 = on->on_next;
+                       on->on_next = oi->oi_list;
+                       oi->oi_list = on;
+               }
+               /* insert */
+               on2->on_next = oi->oi_list;
+               oi->oi_list = on2;
+               if ( otmp1 ) {
+                       *prev = &otmp1->on_next;
+                       /* replace remainder of list */
+                       for ( on=otmp1; on; on=otmp1 ) {
+                               otmp1 = on->on_next;
+                               on->on_next = oi->oi_list;
+                               oi->oi_list = on;
+                       }
+               }
+       }
+}
+
+void
+overlay_move( BackendDB *be, slap_overinst *on, int idx )
+{
+       slap_overinfo *oi = (slap_overinfo *)be->bd_info;
+       slap_overinst **onp;
+
+       for (onp = &oi->oi_list; *onp; onp= &(*onp)->on_next) {
+               if ( *onp == on ) {
+                       *onp = on->on_next;
+                       break;
+               }
+       }
+       overlay_insert( be, on, &onp, idx );
 }
 
 /* add an overlay to a particular backend. */
 int
-overlay_config( BackendDB *be, const char *ov )
+overlay_config( BackendDB *be, const char *ov, int idx, BackendInfo **res, ConfigReply *cr )
 {
-       slap_overinst *on = NULL, *on2 = NULL;
+       slap_overinst *on = NULL, *on2 = NULL, **prev;
        slap_overinfo *oi = NULL;
        BackendInfo *bi = NULL;
 
+       if ( res )
+               *res = NULL;
+
        on = overlay_find( ov );
        if ( !on ) {
                Debug( LDAP_DEBUG_ANY, "overlay \"%s\" not found\n", ov, 0, 0 );
@@ -673,14 +1221,33 @@ overlay_config( BackendDB *be, const char *ov )
         * overlay info structure
         */
        if ( !overlay_is_over( be ) ) {
-               oi = ch_malloc( sizeof( slap_overinfo ) );
-               oi->oi_orig = be->bd_info;
-               oi->oi_bi = *be->bd_info;
+               int     isglobal = 0;
 
                /* NOTE: the first time a global overlay is configured,
                 * frontendDB gets this flag; it is used later by overlays
                 * to determine if they're stacked on top of the frontendDB */
-               if ( oi->oi_orig == frontendDB->bd_info ) {
+               if ( be->bd_info == frontendDB->bd_info || SLAP_ISGLOBALOVERLAY( be ) ) {
+                       isglobal = 1;
+                       if ( on->on_bi.bi_flags & SLAPO_BFLAG_DBONLY ) {
+                               Debug( LDAP_DEBUG_ANY, "overlay_config(): "
+                                       "overlay \"%s\" cannot be global.\n",
+                                       ov, 0, 0 );
+                               return 1;
+                       }
+
+               } else if ( on->on_bi.bi_flags & SLAPO_BFLAG_GLOBONLY ) {
+                       Debug( LDAP_DEBUG_ANY, "overlay_config(): "
+                               "overlay \"%s\" can only be global.\n",
+                               ov, 0, 0 );
+                       return 1;
+               }
+
+               oi = ch_malloc( sizeof( slap_overinfo ) );
+               oi->oi_orig = be->bd_info;
+               oi->oi_bi = *be->bd_info;
+               oi->oi_origdb = be;
+
+               if ( isglobal ) {
                        SLAP_DBFLAGS( be ) |= SLAP_DBFLAG_GLOBAL_OVERLAY;
                }
 
@@ -720,43 +1287,69 @@ overlay_config( BackendDB *be, const char *ov )
                bi->bi_chk_referrals = over_aux_chk_referrals;
                bi->bi_chk_controls = over_aux_chk_controls;
 
-#ifdef SLAP_OVERLAY_ACCESS
-               /* this has a specific arglist */
+               /* these have specific arglists */
+               bi->bi_entry_get_rw = over_entry_get_rw;
+               bi->bi_entry_release_rw = over_entry_release_rw;
                bi->bi_access_allowed = over_access_allowed;
-#endif /* SLAP_OVERLAY_ACCESS */
+               bi->bi_acl_group = over_acl_group;
+               bi->bi_acl_attribute = over_acl_attribute;
                
+               bi->bi_connection_init = over_connection_init;
                bi->bi_connection_destroy = over_connection_destroy;
 
                be->bd_info = bi;
 
        } else {
                if ( overlay_is_inst( be, ov ) ) {
-                       Debug( LDAP_DEBUG_ANY, "overlay_config(): "
-                                       "warning, overlay \"%s\" "
-                                       "already in list\n", ov, 0, 0 );
+                       if ( SLAPO_SINGLE( be ) ) {
+                               Debug( LDAP_DEBUG_ANY, "overlay_config(): "
+                                       "overlay \"%s\" already in list\n",
+                                       ov, 0, 0 );
+                               return 1;
+                       }
                }
 
                oi = be->bd_info->bi_private;
        }
 
-       /* Insert new overlay on head of list. Overlays are executed
-        * in reverse of config order...
+       /* Insert new overlay into list. By default overlays are
+        * added to head of list and executed in LIFO order.
         */
        on2 = ch_calloc( 1, sizeof(slap_overinst) );
        *on2 = *on;
        on2->on_info = oi;
-       on2->on_next = oi->oi_list;
-       oi->oi_list = on2;
+
+       prev = &oi->oi_list;
+       /* Do we need to find the insertion point? */
+       if ( idx >= 0 ) {
+               int i;
+
+               /* count current overlays */
+               for ( i=0, on=oi->oi_list; on; on=on->on_next, i++ );
+
+               /* are we just appending a new one? */
+               if ( idx >= i )
+                       idx = -1;
+       }
+       overlay_insert( be, on2, &prev, idx );
 
        /* Any initialization needed? */
-       if ( on->on_bi.bi_db_init ) {
+       if ( on2->on_bi.bi_db_init ) {
                int rc;
                be->bd_info = (BackendInfo *)on2;
-               rc = on2->on_bi.bi_db_init( be );
+               rc = on2->on_bi.bi_db_init( be, cr);
                be->bd_info = (BackendInfo *)oi;
-               if ( rc ) return rc;
+               if ( rc ) {
+                       *prev = on2->on_next;
+                       ch_free( on2 );
+                       on2 = NULL;
+                       return rc;
+               }
        }
 
+       if ( res )
+               *res = &on2->on_bi;
+
        return 0;
 }