/*
* Copyright (c) OSGi Alliance (2010, 2012). All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.osgi.framework;
import java.io.IOException;
import java.io.NotSerializableException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamField;
import java.security.AccessController;
import java.security.BasicPermission;
import java.security.Permission;
import java.security.PermissionCollection;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* A bundle's authority to adapt an object to a type.
*
* <p>
* {@code AdaptPermission} has one action: {@code adapt}.
*
* @ThreadSafe
* @version $Id: 3bc095bd294db2d8ea25971a3d71991de1495b1a $
*/
public final class AdaptPermission extends BasicPermission {
private static final long serialVersionUID = 1L;
/**
* The action string {@code initiate}.
*/
public final static String ADAPT = "adapt";
private final static int ACTION_ADAPT = 0x00000001;
private final static int ACTION_ALL = ACTION_ADAPT;
final static int ACTION_NONE = 0;
/**
* The actions mask.
*/
transient int action_mask;
/**
* The actions in canonical form.
*
* @serial
*/
private volatile String actions = null;
/**
* The bundle used by this AdaptPermission.
*/
transient final Bundle bundle;
/**
* This holds a Filter matching object used to evaluate the filter in
* implies.
*/
transient Filter filter;
/**
* This map holds the properties of the permission, used to match a filter
* in implies. This is not initialized until necessary, and then cached in
* this object.
*/
private transient volatile Map<String, Object> properties;
/**
* Creates a new granted {@code AdaptPermission} object.
*
* This constructor must only be used to create a permission that is going
* to be checked.
* <p>
* Examples:
*
* <pre>
* (adaptClass=com.acme.*)
* (&(signer=\*,o=ACME,c=US)(adaptClass=com.acme.*))
* (signer=\*,o=ACME,c=US)
* </pre>
*
* <p>
* When a signer key is used within the filter expression the signer value
* must escape the special filter chars ('*', '(', ')').
* <p>
* The name is specified as a filter expression. The filter gives access to
* the following attributes:
* <ul>
* <li>signer - A Distinguished Name chain used to sign the exporting
* bundle. Wildcards in a DN are not matched according to the filter string
* rules, but according to the rules defined for a DN chain.</li>
* <li>location - The location of the exporting bundle.</li>
* <li>id - The bundle ID of the exporting bundle.</li>
* <li>name - The symbolic name of the exporting bundle.</li>
* <li>adaptClass - The name of the type to which an object can be adapted.</li>
* </ul>
* Filter attribute names are processed in a case sensitive manner.
*
* @param filter A filter expression. Filter attribute names are processed
* in a case sensitive manner. A special value of {@code "*"} can be
* used to match all adaptations.
* @param actions {@code adapt}.
* @throws IllegalArgumentException If the filter has an invalid syntax.
*/
public AdaptPermission(String filter, String actions) {
this(parseFilter(filter), parseActions(actions));
}
/**
* Creates a new requested {@code AdaptPermission} object to be used by the
* code that must perform {@code checkPermission}. {@code AdaptPermission}
* objects created with this constructor cannot be added to an
* {@code AdaptPermission} permission collection.
*
* @param adaptClass The name of the type to which an object can be adapted.
* @param adaptableBundle The bundle associated with the object being
* adapted.
* @param actions {@code adapt}.
*/
public AdaptPermission(String adaptClass, Bundle adaptableBundle, String actions) {
super(adaptClass);
setTransients(null, parseActions(actions));
this.bundle = adaptableBundle;
if (adaptClass == null) {
throw new NullPointerException("adaptClass must not be null");
}
if (adaptableBundle == null) {
throw new NullPointerException("adaptableBundle must not be null");
}
}
/**
* Package private constructor used by AdaptPermissionCollection.
*
* @param filter name filter
* @param mask action mask
*/
AdaptPermission(Filter filter, int mask) {
super((filter == null) ? "*" : filter.toString());
setTransients(filter, mask);
this.bundle = null;
}
/**
* Called by constructors and when deserialized.
*
* @param filter Permission's filter or {@code null} for wildcard.
* @param mask action mask
*/
private void setTransients(Filter filter, int mask) {
this.filter = filter;
if ((mask == ACTION_NONE) || ((mask & ACTION_ALL) != mask)) {
throw new IllegalArgumentException("invalid action string");
}
this.action_mask = mask;
}
/**
* Parse action string into action mask.
*
* @param actions Action string.
* @return action mask.
*/
private static int parseActions(String actions) {
boolean seencomma = false;
int mask = ACTION_NONE;
if (actions == null) {
return mask;
}
char[] a = actions.toCharArray();
int i = a.length - 1;
if (i < 0)
return mask;
while (i != -1) {
char c;
// skip whitespace
while ((i != -1) && ((c = a[i]) == ' ' || c == '\r' || c == '\n' || c == '\f' || c == '\t'))
i--;
// check for the known strings
int matchlen;
if (i >= 4 && (a[i - 4] == 'a' || a[i - 4] == 'A')
&& (a[i - 3] == 'd' || a[i - 3] == 'D')
&& (a[i - 2] == 'a' || a[i - 2] == 'A')
&& (a[i - 1] == 'p' || a[i - 1] == 'P')
&& (a[i] == 't' || a[i] == 'T')) {
matchlen = 5;
mask |= ACTION_ADAPT;
} else {
// parse error
throw new IllegalArgumentException("invalid actions: " + actions);
}
// make sure we didn't just match the tail of a word
// like "ackbarfadapt". Also, skip to the comma.
seencomma = false;
while (i >= matchlen && !seencomma) {
switch (a[i - matchlen]) {
case ',' :
seencomma = true;
/* FALLTHROUGH */
case ' ' :
case '\r' :
case '\n' :
case '\f' :
case '\t' :
break;
default :
throw new IllegalArgumentException("invalid permission: " + actions);
}
i--;
}
// point i at the location of the comma minus one (or -1).
i -= matchlen;
}
if (seencomma) {
throw new IllegalArgumentException("invalid actions: " + actions);
}
return mask;
}
/**
* Parse filter string into a Filter object.
*
* @param filterString The filter string to parse.
* @return a Filter for this bundle.
* @throws IllegalArgumentException If the filter syntax is invalid.
*/
private static Filter parseFilter(String filterString) {
filterString = filterString.trim();
if (filterString.equals("*")) {
return null;
}
try {
return FrameworkUtil.createFilter(filterString);
} catch (InvalidSyntaxException e) {
IllegalArgumentException iae = new IllegalArgumentException("invalid filter");
iae.initCause(e);
throw iae;
}
}
/**
* Determines if the specified permission is implied by this object.
*
* <p>
* This method checks that the filter of the target is implied by the adapt
* class name of this object. The list of {@code AdaptPermission} actions
* must either match or allow for the list of the target object to imply the
* target {@code AdaptPermission} action.
* <p>
*
* @param p The requested permission.
* @return {@code true} if the specified permission is implied by this
* object; {@code false} otherwise.
*/
public boolean implies(Permission p) {
if (!(p instanceof AdaptPermission)) {
return false;
}
AdaptPermission requested = (AdaptPermission) p;
if (bundle != null) {
return false;
}
// if requested permission has a filter, then it is an invalid argument
if (requested.filter != null) {
return false;
}
return implies0(requested, ACTION_NONE);
}
/**
* Internal implies method. Used by the implies and the permission
* collection implies methods.
*
* @param requested The requested AdaptPermission which has already be
* validated as a proper argument. The requested AdaptPermission must
* not have a filter expression.
* @param effective The effective actions with which to start.
* @return {@code true} if the specified permission is implied by this
* object; {@code false} otherwise.
*/
boolean implies0(AdaptPermission requested, int effective) {
/* check actions first - much faster */
effective |= action_mask;
final int desired = requested.action_mask;
if ((effective & desired) != desired) {
return false;
}
/* Get filter */
Filter f = filter;
if (f == null) {
// it's "*"
return true;
}
return f.matches(requested.getProperties());
}
/**
* Returns the canonical string representation of the
* {@code AdaptPermission} actions.
*
* <p>
* Always returns present {@code AdaptPermission} actions in the following
* order: {@code adapt}.
*
* @return Canonical string representation of the {@code AdaptPermission}
* actions.
*/
public String getActions() {
String result = actions;
if (result == null) {
actions = result = ADAPT;
}
return result;
}
/**
* Returns a new {@code PermissionCollection} object suitable for storing
* {@code AdaptPermission} objects.
*
* @return A new {@code PermissionCollection} object.
*/
public PermissionCollection newPermissionCollection() {
return new AdaptPermissionCollection();
}
/**
* Determines the equality of two {@code AdaptPermission} objects.
*
* This method checks that specified permission has the same name and
* {@code AdaptPermission} actions as this {@code AdaptPermission} object.
*
* @param obj The object to test for equality with this
* {@code AdaptPermission} object.
* @return {@code true} if {@code obj} is a {@code AdaptPermission}, and has
* the same name and actions as this {@code AdaptPermission} object;
* {@code false} otherwise.
*/
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof AdaptPermission)) {
return false;
}
AdaptPermission cp = (AdaptPermission) obj;
return (action_mask == cp.action_mask) && getName().equals(cp.getName()) && ((bundle == cp.bundle) || ((bundle != null) && bundle.equals(cp.bundle)));
}
/**
* Returns the hash code value for this object.
*
* @return A hash code value for this object.
*/
public int hashCode() {
int h = 31 * 17 + getName().hashCode();
h = 31 * h + getActions().hashCode();
if (bundle != null) {
h = 31 * h + bundle.hashCode();
}
return h;
}
/**
* WriteObject is called to save the state of this permission object to a
* stream. The actions are serialized, and the superclass takes care of the
* name.
*/
private synchronized void writeObject(java.io.ObjectOutputStream s) throws IOException {
if (bundle != null) {
throw new NotSerializableException("cannot serialize");
}
// Write out the actions. The superclass takes care of the name
// call getActions to make sure actions field is initialized
if (actions == null)
getActions();
s.defaultWriteObject();
}
/**
* readObject is called to restore the state of this permission from a
* stream.
*/
private synchronized void readObject(java.io.ObjectInputStream s) throws IOException, ClassNotFoundException {
// Read in the action, then initialize the rest
s.defaultReadObject();
setTransients(parseFilter(getName()), parseActions(actions));
}
/**
* Called by {@code <@link AdaptPermission#implies(Permission)>}. This
* method is only called on a requested permission which cannot have a
* filter set.
*
* @return a map of properties for this permission.
*/
private Map<String, Object> getProperties() {
Map<String, Object> result = properties;
if (result != null) {
return result;
}
final Map<String, Object> map = new HashMap<String, Object>(5);
map.put("adaptClass", getName());
if (bundle != null) {
AccessController.doPrivileged(new PrivilegedAction<Object>() {
public Object run() {
map.put("id", new Long(bundle.getBundleId()));
map.put("location", bundle.getLocation());
String name = bundle.getSymbolicName();
if (name != null) {
map.put("name", name);
}
SignerProperty signer = new SignerProperty(bundle);
if (signer.isBundleSigned()) {
map.put("signer", signer);
}
return null;
}
});
}
return properties = map;
}
}
/**
* Stores a set of {@code AdaptPermission} permissions.
*
* @see java.security.Permission
* @see java.security.Permissions
* @see java.security.PermissionCollection
*/
final class AdaptPermissionCollection extends PermissionCollection {
static final long serialVersionUID = -3350758995234427603L;
/**
* Collection of permissions.
*
* @serial
* @GuardedBy this
*/
private Map<String, AdaptPermission> permissions;
/**
* Boolean saying if "*" is in the collection.
*
* @serial
* @GuardedBy this
*/
private boolean all_allowed;
/**
* Create an empty AdaptPermissions object.
*/
public AdaptPermissionCollection() {
permissions = new HashMap<String, AdaptPermission>();
all_allowed = false;
}
/**
* Adds a permission to this permission collection.
*
* @param permission The {@code AdaptPermission} object to add.
* @throws IllegalArgumentException If the specified permission is not a
* {@code AdaptPermission} instance or was constructed with a Bundle
* object.
* @throws SecurityException If this {@code AdaptPermissionCollection}
* object has been marked read-only.
*/
public void add(final Permission permission) {
if (!(permission instanceof AdaptPermission)) {
throw new IllegalArgumentException("invalid permission: " + permission);
}
if (isReadOnly()) {
throw new SecurityException("attempt to add a Permission to a " + "readonly PermissionCollection");
}
final AdaptPermission ap = (AdaptPermission) permission;
if (ap.bundle != null) {
throw new IllegalArgumentException("cannot add to collection: " + ap);
}
final String name = ap.getName();
synchronized (this) {
Map<String, AdaptPermission> pc = permissions;
final AdaptPermission existing = pc.get(name);
if (existing != null) {
final int oldMask = existing.action_mask;
final int newMask = ap.action_mask;
if (oldMask != newMask) {
pc.put(name, new AdaptPermission(existing.filter, oldMask | newMask));
}
} else {
pc.put(name, ap);
}
if (!all_allowed) {
if (name.equals("*")) {
all_allowed = true;
}
}
}
}
/**
* Determines if the specified permissions implies the permissions expressed
* in {@code permission}.
*
* @param permission The Permission object to compare with this
* {@code AdaptPermission} object.
* @return {@code true} if {@code permission} is a proper subset of a
* permission in the set; {@code false} otherwise.
*/
public boolean implies(final Permission permission) {
if (!(permission instanceof AdaptPermission)) {
return false;
}
final AdaptPermission requested = (AdaptPermission) permission;
/* if requested permission has a filter, then it is an invalid argument */
if (requested.filter != null) {
return false;
}
int effective = AdaptPermission.ACTION_NONE;
Collection<AdaptPermission> perms;
synchronized (this) {
Map<String, AdaptPermission> pc = permissions;
/* short circuit if the "*" Permission was added */
if (all_allowed) {
AdaptPermission ap = pc.get("*");
if (ap != null) {
effective |= ap.action_mask;
final int desired = requested.action_mask;
if ((effective & desired) == desired) {
return true;
}
}
}
perms = pc.values();
}
/* iterate one by one over filteredPermissions */
for (AdaptPermission perm : perms) {
if (perm.implies0(requested, effective)) {
return true;
}
}
return false;
}
/**
* Returns an enumeration of all {@code AdaptPermission} objects in the
* container.
*
* @return Enumeration of all {@code AdaptPermission} objects.
*/
public synchronized Enumeration<Permission> elements() {
List<Permission> all = new ArrayList<Permission>(permissions.values());
return Collections.enumeration(all);
}
/* serialization logic */
private static final ObjectStreamField[] serialPersistentFields = {new ObjectStreamField("permissions", HashMap.class), new ObjectStreamField("all_allowed", Boolean.TYPE)};
private synchronized void writeObject(ObjectOutputStream out) throws IOException {
ObjectOutputStream.PutField pfields = out.putFields();
pfields.put("permissions", permissions);
pfields.put("all_allowed", all_allowed);
out.writeFields();
}
private synchronized void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException {
ObjectInputStream.GetField gfields = in.readFields();
permissions = (HashMap<String, AdaptPermission>) gfields.get("permissions", null);
all_allowed = gfields.get("all_allowed", false);
}
}