Oracle XS$CATVIEW

Oracle XS$CATVIEW_UTIL Version 11.2.0.3

General Information

AUTHID

DEFINER

Data Types

TYPE xs$hash IS TABLE OF BOOLEAN INDEX BY VARCHAR2(5024);

Dependencies

ALL_XSC_SECURITY_CLASS_STATUS	XMLSEQUENCE	XMLTYPE
DUAL	XMLSEQUENCETYPE	XS$SECURITYCLASS
PLITBLM

Security Model

Owned by SYS with EXECUTE granted to SELECT_CATALOG_ROLE

Source

{ORACLE_HOME}/rdbms/admin/xsrelod.sql

Subprograms

DISABLEBYANCESTOR

Package Header

Source Code: Formatted for clarity

CREATE OR REPLACE PACKAGE xs$catview_util AS
FUNCTION disablebyancestor (sc_name   IN VARCHAR2,
                             target_ns IN VARCHAR2,
                             sc_xml     IN XMLType)
RETURN XMLType;
END xs$catview_util;
/

Package Body

Source Code: Formatted for clarity

CREATE OR REPLACE PACKAGE BODY xs$catview_util AS
/* the hash table used for keeping track of visited ancestors used as part of cycle detection in security class */
TYPE xs$hash IS TABLEOFBOOLEAN INDEX BY VARCHAR2(5024);

/* Given a security class xml this function finds whether the security class is disabled by its ancestor. If yes, it returns the ancestor by which the security class is disabled and the ancestors target_namespace */

FUNCTION disablebyancestor_int(visited_list IN OUT xs$hash, sc_xml IN XMLType)
RETURN XMLType IS
enable VARCHAR2(5);
parent VARCHAR2(1024);
parent_target_ns VARCHAR2(4000);
parent_sc_name VARCHAR2(5024);
parent_sc XMLType;
nodelist XMLSequenceType;
result XMLType;
BEGIN
   /* select the parents of the security class in a XMLSequenceType*/
   SELECT XMLSequence(extract(sc_xml,'/securityClass/inherits-from'))
   INTO nodelist
   FROM dual;

   /* loop through the parents */
   FOR x IN 1..nodelist.COUNT() LOOP
     /* get parent name */
   SELECT SUBSTR(REGEXP_REPLACE(extractValue(nodelist(x),
                   '/inherits-from','xmlns="http://xmlns.oracle.com/xs"'),
                   '(.+):(.+)', '\2'),1,1024)
   INTO parent
     FROM dual;

    /* get parent target namespace */
     SELECT SUBSTR(SYS_XMLEXNSURI(nodelist(x),'/inherits-from',
                   'xmlns="http://xmlns.oracle.com/xs"'),1,4000)
   INTO parent_target_ns
   FROM dual;

     parent_sc_name := parent_target_ns ||':'|| parent;
     /* check if there is cycle in security classes i.e there is an entry for parent in hash table */
     IF visited_list.exists(parent_sc_name) THEN
       RETURN XMLType('<disablebyancestor></disablebyancestor>');
     END IF;

     /* put parent in visited list */
     visited_list(parent_sc_name) := TRUE;

     /* beginnig of the exception block */
     BEGIN
       /* get parent securty class xml will throw no data found exception if parent doesn't exist */
       SELECT objeect_value
       INTO parent_sc
       FROM xdb.x$securityclass
       WHERE (SUBSTR(extractValue(OBJECT_VALUE,'/securityClass/@name'),1,1024)=parent)
       AND (SUBSTR(extractValue(OBJECT_VALUE,'/securityClass/@targetNamespace'), 1,4000) = parent_target_ns);

       /* get enable attribute of parent */
       SELECT SUBSTR(extractValue(parent_sc,'/securityClass/@enable'),1,5)
       INTO enable
       FROM dual;

       /* if parent is disabled */
       IF enable = 'false' THEN
         /* return the result as xmltype */
         RETURN XMLType('<disablebyancestor enable="false">
                           <parent>'||parent||'</parent>
                           <parent_target_ns>'||parent_target_ns||' </parent_target_ns>
                         </disablebyancestor>');
         /* if parent is not directly disabled */
       ELSE
         /* check whether it is disabled by its ancestor */
         RESULT := disablebyancestor_int(visited_list,parent_sc);

         /* delete entry from hash table once the recursive call returns */
         visited_list.delete(parent_sc_name);

         /* check the enable attribute in retuirned result */
         SELECT SUBSTR(extractValue(result,'/disablebyancestor/@enable'),1,5)
         INTO enable
         FROM dual;

         /* if parent is disabled by its ancestor or there was a cycle in security class */
         IF (enable = 'false') OR (enable IS NULL) THEN
           RETURN result;
         END IF;
       END IF;

       /* exception is thrown when parent security class is not found */
     EXCEPTION
       WHEN NO_DATA_FOUND THEN
         RETURN XMLTtype('<disablebyancestor></disablebyancestor>');
     END;
   END LOOP;

   /* If security class is not disabled by any of its parent */
   RETURN XMLType('<disablebyancestor enable="true"></disablebyancestor>');
END disablebyancestor_int;

/* Given a security class name and target namespace this function finds whether the security class is disabled by its ancestor
     If security class is disabled by ancestor it returns the ancestor and the target namespace of the ancestor. The result is returned as xmltype */

FUNCTION disablebyancestor(sc_name   IN VARCHAR2,
                            target_ns IN VARCHAR2,
                            sc_xml    IN XMLType)
RETURN XMLType IS
visited_list xs$hash;
result       XMLType;
BEGIN
visited_list(target_ns ||':'|| sc_name) := TRUE;
result := disablebyancestor_int(visited_list,sc_xml);
    RETURN result;
END disablebyancestor;
END xs$catview_util;
/