bees.core
Class Capability

java.lang.Object
  |
  +--bees.core.Capability

Direct Known Subclasses:

AccountSpec, AsymmetricSealer, AsymmetricSealFactory, AsymmetricUnsealer, Clock, Console, EventChannel, FlowIdentifier, FlowIdentifierFactory, bees.core.security.GuardedStringCapability, KeySpec, LoggerSpec, Meter, NeighborImpl, NetworkInterface, NetworkService, NodeOSExternalChannel, NodeSpec, PathSpec, SymmetricSeal, SymmetricSealFactory, SystemClass, SystemPackage

public abstract class Capability

extends java.lang.Object

Base class for capabilities in the system. A "capability" in the context of Bees is an object with the following attributes:

• Controls access to node resources - The main purpose of an Bees capability is to control the effects untrusted code can have on a node.
• Shareable between domains - Domains isolate individual Java objects, a capability provides a means to uniquely reference objects in other domains.
• Serializable - Each capability must be able to flatten its state for storage on disk and transmission to other domains.

Field Summary

static Permission	DELETE_PERMISSION Permission to delete a capability.
protected long	id The unique kernel object store identifier for this capability.
static long	INVALID_ID An invalid capability identifier.

Constructor Summary

protected

Capability() Construct an empty capability.

Method Summary

void	checkPermission(Permission what) Check if this capability has the permissions to do something.
protected void	clear() Clear the internal bits binding this capability to the kernel object.
Permission	clonePermission(Permission what)
void	deleteCapability() Delete a capability.
boolean	equals(java.lang.Object obj)
protected void	fromBytes(byte[] flattened) Bind this capability to the given object.
protected void	fromBytes(byte[] flattened, CapabilityEnvelope[] sub) Bind this capability to the given object.
void	revoke() Revoke access to the capability.
void	revokedPermission(Permission what) Callback...
void	revokePermission(Permission what)
void	revokePermissions(PermissionSet ps)
java.lang.String	toString()
protected boolean	valid()

Methods inherited from class java.lang.Object

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

Field Detail

DELETE_PERMISSION

public static final Permission DELETE_PERMISSION

Permission to delete a capability.

INVALID_ID

public static final long INVALID_ID

An invalid capability identifier.

id

protected long id

The unique kernel object store identifier for this capability.

Constructor Detail

Capability

protected Capability()

Construct an empty capability.

Method Detail

clear

protected void clear()

Clear the internal bits binding this capability to the kernel object.

valid

protected final boolean valid()

Returns:

True if this capability is still valid.

fromBytes

protected void fromBytes(byte[] flattened)
                  throws java.lang.Exception

Bind this capability to the given object.

Parameters:

flattened - The object this capability gives access too.

Throws:

java.lang.Exception - if anything goes wrong during initialization.

fromBytes

protected void fromBytes(byte[] flattened,
                         CapabilityEnvelope[] sub)
                  throws java.lang.Exception

Bind this capability to the given object.

Parameters:

flattened - The object this capability gives access too.

sub - Null or any sub-capabilities.

Throws:

java.lang.Exception - if anything goes wrong during initialization.

revoke

public void revoke()

Revoke access to the capability.

checkPermission

public final void checkPermission(Permission what)
                           throws PermissionException

Check if this capability has the permissions to do something.

Parameters:

what - The permission to check for.

Throws:

PermissionException - if the capability doesn't has the permission.

clonePermission

public final Permission clonePermission(Permission what)
                                 throws PermissionException

Parameters:

what - The permission to clone.

Returns:

A clone of the capabilities Permission that matches the given one.

Throws:

PermissionException - if the capability doesn't has the permission.

revokePermission

public final void revokePermission(Permission what)

Parameters:

what - The Permission to revoke.

revokePermissions

public final void revokePermissions(PermissionSet ps)

Parameters:

ps - The set of Permissions to revoke.

revokedPermission

public void revokedPermission(Permission what)

Callback... XXX Implement me.

deleteCapability

public final void deleteCapability()

Delete a capability.

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

See Also:

Object.equals(Object)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

See Also:

Object.toString()