nachos.security
Class NachosSecurityManager

java.lang.Object
  java.lang.SecurityManager
      nachos.security.NachosSecurityManager

public class NachosSecurityManager
extends SecurityManager

Protects the environment from malicious Nachos code.

Field Summary

Fields inherited from class java.lang.SecurityManager

inCheck

Constructor Summary

NachosSecurityManager(File testDirectory)
Allocate a new Nachos security manager.

Method Summary

void	checkPermission(Permission perm) Check the specified permission.
void	enable() Install this security manager.
Privilege	getPrivilege() Return a privilege object for this security manager.
ThreadGroup	getThreadGroup() Called by the java.lang.Thread constructor to determine a thread group for a child thread of the current thread.
void	verifyPrivilege() Verify that the caller is privileged.
void	verifyPrivilege(Permission perm) Verify that the caller is privileged, so as to check the specified permission.

Methods inherited from class java.lang.SecurityManager

checkAccept, checkAccess, checkAccess, checkAwtEventQueueAccess, checkConnect, checkConnect, checkCreateClassLoader, checkDelete, checkExec, checkExit, checkLink, checkListen, checkMemberAccess, checkMulticast, checkMulticast, checkPackageAccess, checkPackageDefinition, checkPermission, checkPrintJobAccess, checkPropertiesAccess, checkPropertyAccess, checkRead, checkRead, checkRead, checkSecurityAccess, checkSetFactory, checkSystemClipboardAccess, checkTopLevelWindow, checkWrite, checkWrite, classDepth, classLoaderDepth, currentClassLoader, currentLoadedClass, getClassContext, getInCheck, getSecurityContext, inClass, inClassLoader

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

NachosSecurityManager

public NachosSecurityManager(File testDirectory)

Allocate a new Nachos security manager.

Parameters:

testDirectory - the directory usable by the stub file system.

Method Detail

getPrivilege

public Privilege getPrivilege()

Return a privilege object for this security manager. This security manager must not be the active security manager.

Returns:

a privilege object for this security manager.

enable

public void enable()

Install this security manager.

checkPermission

public void checkPermission(Permission perm)

Check the specified permission. Some operations are permissible while not grading. These operations are regulated here.

Overrides:

checkPermission in class SecurityManager

Parameters:

perm - the permission to check.

getThreadGroup

public ThreadGroup getThreadGroup()

Called by the java.lang.Thread constructor to determine a thread group for a child thread of the current thread. The caller must be privileged in order to successfully create the thread.

Overrides:

getThreadGroup in class SecurityManager

Returns:

a thread group for the new thread, or null to use the current thread's thread group.

verifyPrivilege

public void verifyPrivilege()

Verify that the caller is privileged.

verifyPrivilege

public void verifyPrivilege(Permission perm)

Verify that the caller is privileged, so as to check the specified permission.

Parameters:

perm - the permission being checked.