3 Copyright © 2004, Oracle. All rights reserved. Controlling Access to the Oracle Listener

3Copyright © 2004, Oracle. All rights reserved.

Controlling Access to the Oracle Listener

3-2 Copyright © 2004, Oracle. All rights reserved.

Objectives

After completing this lesson, you should be able to do the following:

• Secure the listener

• Enable TCP valid node checking

• Remove default EXTPROC entry

• Add a separate listener to handle external procedure calls


Oracle Net Services Review

Application

Oracle Net

RDBMS

Oracle Net

Client Database server

TCP/IP network

Listener

tnsnames.orasqlnet.ora listener.ora


Listener Password Authentication

• In Oracle Database 10g, the listener is secure by default.

• Operating system authentication is used.

• Listener passwords are still supported if needed.– Use listener control utility lsnrctl– Use EM Database Control– Use Oracle Net Manager


Setting Listener Password

Using Enterprise Manager


Setting Listener Password with Net Manager


Set Password with lsnrctl Utility

Using the lsnrctl CHANGE_PASSWORD command:

$ lsnrctlLSNRCTL> CHANGE_PASSWORDOld password: *******New Password: 1tsaSafe1Reenter new password: 1tsaSafe1LSNRCTL> SAVE_CONFIG


Controlling Database Access


Oracle Net Services External Procedures

• External procedures that are called from a program, but are written in a different language

• The listener must be configured to listen for external procedure calls

• Listener starts an external procedure agent

• Default agent name is EXTPROC


Overview of the EXTPROC Agent

• It services execution of external procedures for the duration of the session until the user logs off.

• Each session uses a different EXTPROC agent to execute external procedures.

• The listener must be configured to allow the server to be associated with the EXTPROC agent.

• The listener must be on the same machine as the server.


1

PL/SQL subprogram

Aliaslibrary

23

4

EXTPROCagent

Userprocess

PL/SQL Calling a C External Procedure

Shared library

5

Externalprocedure

6

7

Listenerprocess

BEGIN myproc


Default Configuration for External Procedure Calls

• Listener is configured to accept requests for external procedures by Oracle Net Configuration Assistant during installation.

• A net service name is configured in the tnsnames.ora file.

EXTPROC_CONNECTION_DATA= (DESCRIPTION= (ADDRESS=(PROTOCOL=ipc)(KEY=extproc)) (CONNECT_DATA= (SID=plsextproc)))


Modifying the Configuration forExternal Procedure Calls

1. Remove the external procedure entries for the default listener.

2. Configure a separate listener dedicated to servicing external procedures.

3. Configure listener to run with privileges lower than those of the listener for the database.

4. Restrict the DLLs that the EXTPROC agent can load.


Remove Default EXTPROC Entry

Using Enterprise Manager:


Remove Default EXTPROC Entry

Using Net Manager


Configure a Dedicated Listener for External Procedure Calls







Using Net Manager


Summary

In this lesson, you should have learned how to:

• Secure the listener

• Enable TCP valid node checking

• Remove default EXTPROC entry

• Add a separate listener to handle external procedure calls


Practice 3 Overview: Controlling Access to the Listener

This practice covers the following topics:

• Password protecting listener management tasks

• Removing the default EXTPROC listener service

• Creating a dedicated listener for external procedures

• Controlling database access

Documents

3 Copyright © 2004, Oracle. All rights reserved. Controlling Access to the Oracle Listener