text: /* -------------------------------------------------------------------------
   *
   * contrib/sepgsql/database.c
   *
   * Routines corresponding to database objects
   *
   * Copyright (c) 2010-2017, PostgreSQL Global Development Group
   *
   * -------------------------------------------------------------------------
   */
  #include "postgres.h"
  
  #include "access/genam.h"
  #include "access/heapam.h"
  #include "access/htup_details.h"
  #include "access/sysattr.h"
  #include "catalog/dependency.h"
  #include "catalog/pg_database.h"
  #include "catalog/indexing.h"
  #include "commands/dbcommands.h"
  #include "commands/seclabel.h"
  #include "utils/builtins.h"
  #include "utils/fmgroids.h"
  #include "utils/tqual.h"
  #include "sepgsql.h"
  
  /*
   * sepgsql_database_post_create
   *
   * This routine assigns a default security label on a newly defined
   * database, and check permission needed for its creation.
   */
  void
  sepgsql_database_post_create(Oid databaseId, const char *dtemplate)
  {
      Relation    rel;
      ScanKeyData skey;
      SysScanDesc sscan;
      HeapTuple    tuple;
      char       *tcontext;
      char       *ncontext;
      ObjectAddress object;
      Form_pg_database datForm;
      StringInfoData audit_name;
  
      /*
       * Oid of the source database is not saved in pg_database catalog, so we
       * collect its identifier using contextual information. If NULL, its
       * default is "template1" according to createdb().
       */
      if (!dtemplate)
          dtemplate = "template1";
  
      object.classId = DatabaseRelationId;
      object.objectId = get_database_oid(dtemplate, false);
      object.objectSubId = 0;
  
      tcontext = sepgsql_get_label(object.classId,
                                   object.objectId,
                                   object.objectSubId);
  
      /*
       * check db_database:{getattr} permission
       */
      initStringInfo(&audit_name);
      appendStringInfo(&audit_name, "%s", quote_identifier(dtemplate));
      sepgsql_avc_check_perms_label(tcontext,
                                    SEPG_CLASS_DB_DATABASE,
                                    SEPG_DB_DATABASE__GETATTR,
                                    audit_name.data,
                                    true);
  
      /*
       * Compute a default security label of the newly created database based on
       * a pair of security label of client and source database.
       *
       * XXX - uncoming version of libselinux supports to take object name to
       * handle special treatment on default security label.
       */
      rel = heap_open(DatabaseRelationId, AccessShareLock);
  
      ScanKeyInit(&skey,
                  ObjectIdAttributeNumber,
                  BTEqualStrategyNumber, F_OIDEQ,
                  ObjectIdGetDatum(databaseId));
  
      sscan = systable_beginscan(rel, DatabaseOidIndexId, true,
                                 SnapshotSelf, 1, &skey);
      tuple = systable_getnext(sscan);
      if (!HeapTupleIsValid(tuple))
          elog(ERROR, "could not find tuple for database %u", databaseId);
  
      datForm = (Form_pg_database) GETSTRUCT(tuple);
  
      ncontext = sepgsql_compute_create(sepgsql_get_client_label(),
                                        tcontext,
                                        SEPG_CLASS_DB_DATABASE,
                                        NameStr(datForm->datname));
  
      /*
       * check db_database:{create} permission
       */
      resetStringInfo(&audit_name);
      appendStringInfo(&audit_name, "%s",
                       quote_identifier(NameStr(datForm->datname)));
      sepgsql_avc_check_perms_label(ncontext,
                                    SEPG_CLASS_DB_DATABASE,
                                    SEPG_DB_DATABASE__CREATE,
                                    audit_name.data,
                                    true);
  
      systable_endscan(sscan);
      heap_close(rel, AccessShareLock);
  
      /*
       * Assign the default security label on the new database
       */
      object.classId = DatabaseRelationId;
      object.objectId = databaseId;
      object.objectSubId = 0;
  
      SetSecurityLabel(&object, SEPGSQL_LABEL_TAG, ncontext);
  
      pfree(ncontext);
      pfree(tcontext);
  }
  
  /*
   * sepgsql_database_drop
   *
   * It checks privileges to drop the supplied database
   */
  void
  sepgsql_database_drop(Oid databaseId)
  {
      ObjectAddress object;
      char       *audit_name;
  
      /*
       * check db_database:{drop} permission
       */
      object.classId = DatabaseRelationId;
      object.objectId = databaseId;
      object.objectSubId = 0;
      audit_name = getObjectIdentity(&object);
  
      sepgsql_avc_check_perms(&object,
                              SEPG_CLASS_DB_DATABASE,
                              SEPG_DB_DATABASE__DROP,
                              audit_name,
                              true);
      pfree(audit_name);
  }
  
  /*
   * sepgsql_database_post_alter
   *
   * It checks privileges to alter the supplied database
   */
  void
  sepgsql_database_setattr(Oid databaseId)
  {
      ObjectAddress object;
      char       *audit_name;
  
      /*
       * check db_database:{setattr} permission
       */
      object.classId = DatabaseRelationId;
      object.objectId = databaseId;
      object.objectSubId = 0;
      audit_name = getObjectIdentity(&object);
  
      sepgsql_avc_check_perms(&object,
                              SEPG_CLASS_DB_DATABASE,
                              SEPG_DB_DATABASE__SETATTR,
                              audit_name,
                              true);
      pfree(audit_name);
  }
  
  /*
   * sepgsql_database_relabel
   *
   * It checks privileges to relabel the supplied database with the `seclabel'
   */
  void
  sepgsql_database_relabel(Oid databaseId, const char *seclabel)
  {
      ObjectAddress object;
      char       *audit_name;
  
      object.classId = DatabaseRelationId;
      object.objectId = databaseId;
      object.objectSubId = 0;
      audit_name = getObjectIdentity(&object);
  
      /*
       * check db_database:{setattr relabelfrom} permission
       */
      sepgsql_avc_check_perms(&object,
                              SEPG_CLASS_DB_DATABASE,
                              SEPG_DB_DATABASE__SETATTR |
                              SEPG_DB_DATABASE__RELABELFROM,
                              audit_name,
                              true);
  
      /*
       * check db_database:{relabelto} permission
       */
      sepgsql_avc_check_perms_label(seclabel,
                                    SEPG_CLASS_DB_DATABASE,
                                    SEPG_DB_DATABASE__RELABELTO,
                                    audit_name,
                                    true);
      pfree(audit_name);
  }
  