Framework for loadable mapper implementations

include/rewrite.h

@@ -253,6 +253,46 @@ rewrite_param_destroy(
                 struct rewrite_info *info
 );
 
+/*
+ * Mapping implementations
+ */
+
+struct rewrite_mapper;
+
+typedef void * (rewrite_mapper_config)(
+	const char *fname,
+	int lineno,
+	int argc,
+	char **argv );
+
+typedef int (rewrite_mapper_apply)(
+	void *ctx,
+	const char *arg,
+	struct berval *retval );
+
+typedef int (rewrite_mapper_destroy)(
+	void *ctx );
+
+typedef struct rewrite_mapper {
+	char *rm_name;
+	rewrite_mapper_config *rm_config;
+	rewrite_mapper_apply *rm_apply;
+	rewrite_mapper_destroy *rm_destroy;
+} rewrite_mapper;
+
+/* For dynamic loading and unloading of mappers */
+LDAP_REWRITE_F (int)
+rewrite_mapper_register(
+	const rewrite_mapper *map );
+
+LDAP_REWRITE_F (int)
+rewrite_mapper_unregister(
+	const rewrite_mapper *map );
+
+LDAP_REWRITE_F (const rewrite_mapper *)
+rewrite_mapper_find(
+	const char *name );
+
 LDAP_END_DECL
 
 #endif /* REWRITE_H */

libraries/librewrite/config.c

@@ -413,8 +413,8 @@ rewrite_parse_builtin_map(
 	/*
 	 * Built-in ldap map
 	 */
-	if ( strcasecmp( argv[ MAP_TYPE ], "ldap" ) == 0 ) {
-		map->lb_type = REWRITE_BUILTIN_MAP_LDAP;
+	if (( map->lb_mapper = rewrite_mapper_find( argv[ MAP_TYPE ] ))) {
+		map->lb_type = REWRITE_BUILTIN_MAP;
 
 #ifdef USE_REWRITE_LDAP_PVT_THREADS
 		if ( ldap_pvt_thread_mutex_init( & map->lb_mutex ) ) {
@@ -424,7 +424,7 @@ rewrite_parse_builtin_map(
 		}
 #endif /* USE_REWRITE_LDAP_PVT_THREADS */
 		
-		map->lb_private = map_ldap_parse( info, fname, lineno,
+		map->lb_private = map->lb_mapper->rm_config( fname, lineno,
 				argc - 3, argv + 3 );
 		
 	/* 

libraries/librewrite/ldapmap.c

@@ -85,9 +85,8 @@ map_ldap_free(
 	free( data );
 }
 
-void *
+static void *
 map_ldap_parse(
-		struct rewrite_info *info,
 		const char *fname,
 		int lineno,
 		int argc,
@@ -97,7 +96,6 @@ map_ldap_parse(
 	struct ldap_map_data *data;
 	char *p, *uri;
 
-	assert( info != NULL );
 	assert( fname != NULL );
 	assert( argv != NULL );
 
@@ -285,9 +283,9 @@ map_ldap_parse(
 	return ( void * )data;
 }
 
-int
+static int
 map_ldap_apply(
-		struct rewrite_builtin_map *map,
+		void *private,
 		const char *filter,
 		struct berval *val
 
@@ -296,14 +294,12 @@ map_ldap_apply(
 	LDAP *ld;
 	LDAPMessage *res = NULL, *entry;
 	int rc;
-	struct ldap_map_data *data = ( struct ldap_map_data * )map->lb_private;
+	struct ldap_map_data *data = private;
 	LDAPURLDesc *lud = data->lm_lud;
 	
 	int first_try = 1, set_version = 0;
 
-	assert( map != NULL );
-	assert( map->lb_type == REWRITE_BUILTIN_MAP_LDAP );
-	assert( map->lb_private != NULL );
+	assert( private != NULL );
 	assert( filter != NULL );
 	assert( val != NULL );
 
@@ -435,22 +431,24 @@ rc_return:;
 	return rc;
 }
 
-int
+static int
 map_ldap_destroy(
-		struct rewrite_builtin_map **pmap
+		void *private
 )
 {
-	struct ldap_map_data *data;
+	struct ldap_map_data *data = private;
 
-	assert( pmap != NULL );
-	assert( *pmap != NULL );
+	assert( private != NULL );
 	
-	data = ( struct ldap_map_data * )(*pmap)->lb_private;
-
 	map_ldap_free( data );
 
-	(*pmap)->lb_private = NULL;
-
 	return 0;
 }
 
+const rewrite_mapper rewrite_ldap_mapper = {
+	"ldap",
+	map_ldap_parse,
+	map_ldap_apply,
+	map_ldap_destroy
+};
+

libraries/librewrite/map.c

@@ -28,6 +28,10 @@
 #include "rewrite-int.h"
 #include "rewrite-map.h"
 
+static int num_mappers;
+static const rewrite_mapper **mappers;
+#define	MAPPER_ALLOC	8
+
 struct rewrite_map *
 rewrite_map_parse(
 		struct rewrite_info *info,
@@ -417,14 +421,12 @@ rewrite_map_apply(
 	case REWRITE_MAP_BUILTIN: {
 		struct rewrite_builtin_map *bmap = map->lm_data;
 
-		switch ( bmap->lb_type ) {
-		case REWRITE_BUILTIN_MAP_LDAP:
-			rc = map_ldap_apply( bmap, key->bv_val, val );
-			break;
-		default:
+		if ( bmap->lb_mapper && bmap->lb_mapper->rm_apply )
+			rc = bmap->lb_mapper->rm_apply( bmap->lb_private, key->bv_val,
+				val );
+		else
 			rc = REWRITE_ERR;
 			break;
-		}
 		break;
 	}
 
@@ -445,15 +447,8 @@ rewrite_builtin_map_free(
 
 	assert( map != NULL );
 
-	switch ( map->lb_type ) {
-	case REWRITE_BUILTIN_MAP_LDAP:
-		map_ldap_destroy( &map );
-		break;
-
-	default:
-		assert(0);
-		break;
-	}
+	if ( map->lb_mapper && map->lb_mapper->rm_destroy )
+		map->lb_mapper->rm_destroy( map->lb_private );
 
 	free( map->lb_name );
 	free( map );
@@ -495,3 +490,58 @@ rewrite_map_destroy(
 	return 0;
 }
 
+/* ldapmap.c */
+extern const rewrite_mapper rewrite_ldap_mapper;
+
+const rewrite_mapper *
+rewrite_mapper_find(
+	const char *name
+)
+{
+	int i;
+
+	if ( !strcasecmp( name, "ldap" ))
+		return &rewrite_ldap_mapper;
+
+	for (i=0; i<num_mappers; i++)
+		if ( !strcasecmp( name, mappers[i]->rm_name ))
+			return mappers[i];
+	return NULL;
+}
+
+int
+rewrite_mapper_register(
+	const rewrite_mapper *map
+)
+{
+	if ( num_mappers % MAPPER_ALLOC == 0 ) {
+		const rewrite_mapper **mnew;
+		mnew = realloc( mappers, (num_mappers + MAPPER_ALLOC) *
+			sizeof( rewrite_mapper * ));
+		if ( mnew )
+			mappers = mnew;
+		else
+			return -1;
+	}
+	mappers[num_mappers++] = map;
+	return 0;
+}
+
+int
+rewrite_mapper_unregister(
+	const rewrite_mapper *map
+)
+{
+	int i;
+
+	for (i = 0; i<num_mappers; i++) {
+		if ( mappers[i] == map ) {
+			num_mappers--;
+			mappers[i] = mappers[num_mappers];
+			mappers[num_mappers] = NULL;
+			return 0;
+		}
+	}
+	/* not found */
+	return -1;
+}

libraries/librewrite/rewrite-int.h

@@ -157,10 +157,11 @@ struct rewrite_map {
  * Builtin maps
  */
 struct rewrite_builtin_map {
-#define REWRITE_BUILTIN_MAP_LDAP	0x0201
+#define REWRITE_BUILTIN_MAP	0x0200
 	int                             lb_type;
 	char                           *lb_name;
 	void                           *lb_private;
+	const rewrite_mapper		   *lb_mapper;
 
 #ifdef USE_REWRITE_LDAP_PVT_THREADS
 	ldap_pvt_thread_mutex_t         lb_mutex;

libraries/librewrite/rewrite-map.h

@@ -29,26 +29,4 @@ rewrite_builtin_map_find(
                 const char *name
 );
 
-
-/*
- * LDAP map
- */
-LDAP_REWRITE_F (void  *)
-map_ldap_parse(
-		struct rewrite_info *info,
-		const char *fname,
-		int lineno,
-	       	int argc,
-	       	char **argv
-);
-
-LDAP_REWRITE_F (int)
-map_ldap_apply( struct rewrite_builtin_map *map,
-		const char *filter,
-		struct berval *val
-);
-
-LDAP_REWRITE_F (int)
-map_ldap_destroy( struct rewrite_builtin_map **map );
-
 #endif /* MAP_H */