added callbacks to most of the functions; more cleanup

servers/slapd/back-relay/README

-Relay backend automatically sets up a rewrite-remap overlay that maps 
-the virtual naming context to a real naming context that is available
-in the same server
+Relay backend sets up a relay virtual database that allows
+to access other databases in the same instance of slapd
+through different naming contexts and remapping attribute 
+values.
+
+The DN rewrite, filter rewrite and attributeType/objectClass
+mapping is done by means of the rewrite-remap overlay.
+
+The database containing the real naming context can be
+explicitly selected by means of the "relay" directive,
+which must contain the naming context of the target 
+database.  This also causes the rewrite-remap overlay 
+to be automatically instantiated.  If the optional keyword 
+"massage" is present, the rewrite-remap overlay is 
+automatically configured to map the virtual to the real 
+naming context and vice-versa; in this case, the "suffix" 
+directive must precede the "relay" directive.
+
+Otherwise, the rewrite-remap overlay must be explicitly
+instantiated, by using the "overlay" directive, as 
+illustrated below.  This allows much more freedom in target 
+database selection and DN rewriting.
+
+If the "relay" directive is not present, the backend is
+not bound to a single target database; on the contrary,
+the target database is selected on a per-operation basis.
+
+This allows, for instance, to relay one database for 
+authentication and anothe for search/modify, or allows
+to use one target for persons and another for groups
+and so on.
 
 # automatically massage from virtual to real naming context
 database	relay
 suffix		"dc=virtual,dc=naming,dc=context"
-relay		"dc=real,dc=naming,dc=context"
+relay		"dc=real,dc=naming,dc=context" massage
 
-# explicitly massage
+# explicitly massage (same as above)
 database	relay
 suffix		"dc=virtual,dc=naming,dc=context"
 overlay		rewrite-remap
-suffixmassage	"dc=virtual,dc=naming,dc=context" "dc=real,dc=naming,dc=context"
+suffixmassage	"dc=virtual,dc=naming,dc=context" \
+			"dc=real,dc=naming,dc=context"
 
-# old fashioned suffixalias...
+# old fashioned suffixalias, applied also to DN-valued attributes
+# from virtual to real naming context, but not the reverse...
 database	relay
 suffix		"dc=virtual,dc=naming,dc=context"
 overlay		rewrite-remap
 rewriteEngine	on
 rewriteContext	default
 rewriteRule	"(.*)dc=virtual,dc=naming,dc=context$" \
-			"\1dc=real,dc=naming,dc=context"
+			"$1dc=real,dc=naming,dc=context"
 

servers/slapd/back-relay/config.c

@@ -22,12 +22,8 @@
 
 #include <stdio.h>
 
-#include <ac/string.h>
-#include <ac/socket.h>
-
 #include "slap.h"
 #include "back-relay.h"
-#include "lutil.h"
 
 int
 relay_back_db_config(
@@ -43,20 +39,25 @@ relay_back_db_config(
 	if ( ri == NULL ) {
 		fprintf( stderr, "%s: line %d: relay backend info is null!\n",
 		    fname, lineno );
-		return( 1 );
+		return 1;
 	}
 
 	/* real naming context */
 	if ( strcasecmp( argv[0], "relay" ) == 0 ) {
 		struct berval	dn, ndn, pdn;
 		int		rc;
-		char		*cargv[ 4 ];
 
-		if (argc != 2) {
+		if ( argc < 2 ) {
+			fprintf( stderr,
+	"%s: line %d: missing relay suffix in \"relay <dn> [massage]\" line\n",
+			    fname, lineno );
+			return 1;
+
+		} else if ( argc > 3 ) {
 			fprintf( stderr,
-	"%s: line %d: missing relay suffix in \"relay <dn>\" line\n",
+	"%s: line %d: too many args in \"relay <dn> [massage]\" line\n",
 			    fname, lineno );
-			return( 1 );
+			return 1;
 		}
 
 		dn.bv_val = argv[ 1 ];
@@ -85,22 +86,39 @@ relay_back_db_config(
 		} 
 
 		if ( overlay_config( be, "rewrite-remap" ) ) {
-			fprintf( stderr, "unable to install "
+			fprintf( stderr, "%s: line %d: unable to install "
 					"rewrite-remap overlay "
-					"in back-relay \"%s\" => \"%s\"\n",
-					be->be_suffix[0].bv_val,
-					ri->ri_bd->be_suffix[0].bv_val ? 
-					ri->ri_bd->be_suffix[0].bv_val : "<unknown>" );
+					"in back-relay\n",
+					fname, lineno );
 			return 1;
 		}
 
-		cargv[ 0 ] = "suffixmassage";
-		cargv[ 1 ] = be->be_suffix[0].bv_val;
-		cargv[ 2 ] = ri->ri_bd->be_suffix[0].bv_val;
-		cargv[ 3 ] = NULL;
-
-		if ( be->be_config( be, "back-relay", 1, 3, cargv ) ) {
-			return 1;
+		if ( argc == 3 ) {
+			char	*cargv[ 4 ];
+
+			if ( strcmp( argv[2], "massage" ) ) {
+				fprintf( stderr, "%s: line %d: "
+					"unknown directive \"%s\" "
+					"in \"relay <dn> [massage]\" line\n",
+					fname, lineno, argv[2] );
+				return 1;
+			}
+
+			if ( be->be_suffix[0].bv_val == NULL ) {
+				fprintf( stderr, "%s: line %d: "
+					"relay line must come after \"suffix\"\n",
+					fname, lineno );
+				return 1;
+			}
+
+			cargv[ 0 ] = "suffixmassage";
+			cargv[ 1 ] = be->be_suffix[0].bv_val;
+			cargv[ 2 ] = ri->ri_bd->be_suffix[0].bv_val;
+			cargv[ 3 ] = NULL;
+
+			if ( be->be_config( be, "back-relay", 1, 3, cargv ) ) {
+				return 1;
+			}
 		}
 
 	/* anything else */

servers/slapd/back-relay/init.c

@@ -22,9 +22,6 @@
 
 #include <stdio.h>
 
-#include <ac/string.h>
-#include <ac/socket.h>
-
 #include "slap.h"
 #include "back-relay.h"
 

servers/slapd/back-relay/op.c

@@ -22,9 +22,6 @@
 
 #include <stdio.h>
 
-#include <ac/string.h>
-#include <ac/socket.h>
-
 #include "slap.h"
 #include "back-relay.h"
 
@@ -126,6 +123,13 @@ relay_back_op_unbind( struct slap_op *op, struct slap_rep *rs )
 
 	if ( bd && bd->be_unbind ) {
 		BackendDB	*be = op->o_bd;
+		slap_callback	cb;
+
+		cb.sc_next = op->o_callback;
+		cb.sc_response = relay_back_swap_bd;
+		cb.sc_cleanup = relay_back_swap_bd;
+		cb.sc_private = op->o_bd;
+		op->o_callback = &cb;
 
 		op->o_bd = bd;
 		rc = ( bd->be_unbind )( op, rs );
@@ -184,6 +188,13 @@ relay_back_op_compare( struct slap_op *op, struct slap_rep *rs )
 
 	if ( bd->be_compare ) {
 		BackendDB	*be = op->o_bd;
+		slap_callback	cb;
+
+		cb.sc_next = op->o_callback;
+		cb.sc_response = relay_back_swap_bd;
+		cb.sc_cleanup = relay_back_swap_bd;
+		cb.sc_private = op->o_bd;
+		op->o_callback = &cb;
 
 		op->o_bd = bd;
 		rc = ( bd->be_compare )( op, rs );
@@ -212,6 +223,13 @@ relay_back_op_modify( struct slap_op *op, struct slap_rep *rs )
 
 	if ( bd->be_modify ) {
 		BackendDB	*be = op->o_bd;
+		slap_callback	cb;
+
+		cb.sc_next = op->o_callback;
+		cb.sc_response = relay_back_swap_bd;
+		cb.sc_cleanup = relay_back_swap_bd;
+		cb.sc_private = op->o_bd;
+		op->o_callback = &cb;
 
 		op->o_bd = bd;
 		rc = ( bd->be_modify )( op, rs );
@@ -240,6 +258,13 @@ relay_back_op_modrdn( struct slap_op *op, struct slap_rep *rs )
 
 	if ( bd->be_modrdn ) {
 		BackendDB	*be = op->o_bd;
+		slap_callback	cb;
+
+		cb.sc_next = op->o_callback;
+		cb.sc_response = relay_back_swap_bd;
+		cb.sc_cleanup = relay_back_swap_bd;
+		cb.sc_private = op->o_bd;
+		op->o_callback = &cb;
 
 		op->o_bd = bd;
 		rc = ( bd->be_modrdn )( op, rs );
@@ -268,6 +293,13 @@ relay_back_op_add( struct slap_op *op, struct slap_rep *rs )
 
 	if ( bd->be_add ) {
 		BackendDB	*be = op->o_bd;
+		slap_callback	cb;
+
+		cb.sc_next = op->o_callback;
+		cb.sc_response = relay_back_swap_bd;
+		cb.sc_cleanup = relay_back_swap_bd;
+		cb.sc_private = op->o_bd;
+		op->o_callback = &cb;
 
 		op->o_bd = bd;
 		rc = ( bd->be_add )( op, rs );
@@ -296,6 +328,13 @@ relay_back_op_delete( struct slap_op *op, struct slap_rep *rs )
 
 	if ( bd->be_delete ) {
 		BackendDB	*be = op->o_bd;
+		slap_callback	cb;
+
+		cb.sc_next = op->o_callback;
+		cb.sc_response = relay_back_swap_bd;
+		cb.sc_cleanup = relay_back_swap_bd;
+		cb.sc_private = op->o_bd;
+		op->o_callback = &cb;
 
 		op->o_bd = bd;
 		rc = ( bd->be_delete )( op, rs );
@@ -319,6 +358,13 @@ relay_back_op_abandon( struct slap_op *op, struct slap_rep *rs )
 
 	if ( bd->be_abandon ) {
 		BackendDB	*be = op->o_bd;
+		slap_callback	cb;
+
+		cb.sc_next = op->o_callback;
+		cb.sc_response = relay_back_swap_bd;
+		cb.sc_cleanup = relay_back_swap_bd;
+		cb.sc_private = op->o_bd;
+		op->o_callback = &cb;
 
 		op->o_bd = bd;
 		rc = ( bd->be_abandon )( op, rs );
@@ -347,6 +393,13 @@ relay_back_op_cancel( struct slap_op *op, struct slap_rep *rs )
 
 	if ( bd->be_cancel ) {
 		BackendDB	*be = op->o_bd;
+		slap_callback	cb;
+
+		cb.sc_next = op->o_callback;
+		cb.sc_response = relay_back_swap_bd;
+		cb.sc_cleanup = relay_back_swap_bd;
+		cb.sc_private = op->o_bd;
+		op->o_callback = &cb;
 
 		op->o_bd = bd;
 		rc = ( bd->be_cancel )( op, rs );
@@ -375,6 +428,13 @@ relay_back_op_extended( struct slap_op *op, struct slap_rep *rs )
 
 	if ( bd->be_extended ) {
 		BackendDB	*be = op->o_bd;
+		slap_callback	cb;
+
+		cb.sc_next = op->o_callback;
+		cb.sc_response = relay_back_swap_bd;
+		cb.sc_cleanup = relay_back_swap_bd;
+		cb.sc_private = op->o_bd;
+		op->o_callback = &cb;
 
 		op->o_bd = bd;
 		rc = ( bd->be_extended )( op, rs );
@@ -458,6 +518,13 @@ relay_back_chk_referrals( struct slap_op *op, struct slap_rep *rs )
 
 	if ( bd->be_chk_referrals ) {
 		BackendDB	*be = op->o_bd;
+		slap_callback	cb;
+
+		cb.sc_next = op->o_callback;
+		cb.sc_response = relay_back_swap_bd;
+		cb.sc_cleanup = relay_back_swap_bd;
+		cb.sc_private = op->o_bd;
+		op->o_callback = &cb;
 
 		op->o_bd = bd;
 		rc = ( bd->be_chk_referrals )( op, rs );