/*
* Copyright (c) OSGi Alliance (2000, 2010). 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.service.remoteserviceadmin;
import static org.osgi.service.remoteserviceadmin.RemoteConstants.*;
import java.io.IOException;
import java.io.NotSerializableException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamField;
import java.security.Permission;
import java.security.PermissionCollection;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Dictionary;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;
import org.osgi.framework.Filter;
import org.osgi.framework.FrameworkUtil;
import org.osgi.framework.InvalidSyntaxException;
/**
* A bundle's authority to export, import or read an Endpoint.
* <ul>
* <li>The <code>export</code> action allows a bundle to export a service as an
* Endpoint.</li>
* <li>The <code>import</code> action allows a bundle to import a service from
* an Endpoint.</li>
* <li>The <code>read</code> action allows a bundle to read references to an
* Endpoint.</li>
* </ul>
* Permission to read an Endpoint is required in order to detect events
* regarding an Endpoint. Untrusted bundles should not be able to detect the
* presence of certain Endpoints unless they have the appropriate
* <code>EndpointPermission</code> to read the specific service.
*
* @ThreadSafe
* @version $Revision: 925633 $
*/
public final class EndpointPermission extends Permission {
static final long serialVersionUID = -7662148639076511574L;
/**
* The action string <code>read</code>.
*/
public final static String READ = "read";
/**
* The action string <code>import</code>. The <code>import</code> action
* implies the <code>read</code> action.
*/
public final static String IMPORT = "import";
/**
* The action string <code>export</code>. The <code>export</code> action
* implies the <code>read</code> action.
*/
public final static String EXPORT = "export";
private final static int ACTION_READ = 0x00000001;
private final static int ACTION_IMPORT = 0x00000002;
private final static int ACTION_EXPORT = 0x00000004;
private final static int ACTION_ALL = ACTION_EXPORT
| ACTION_IMPORT
| ACTION_READ;
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 endpoint used by this EndpointPermission. Must be <code>null</code>
* if not constructed with a endpoint.
*/
transient final EndpointDescription endpoint;
/**
* This dictionary holds the properties of the permission, used to match a
* filter in implies.
*/
private transient final Dictionary<String, Object> properties;
/**
* If this EndpointPermission was not constructed with an
* EndpointDescription, this holds a Filter matching object used to evaluate
* the filter in implies or <code>null</code> for wildcard.
*/
transient Filter filter;
/**
* Create a new EndpointPermission with the specified filter.
*
* <p>
* The filter will be evaluated against the endpoint properties of a
* requested EndpointPermission.
*
* <p>
* There are three possible actions: <code>read</code>, <code>import</code>
* and <code>export</code>. The <code>read</code> action allows the owner of
* this permission to see the presence of distributed services. The
* <code>import</code> action allows the owner of this permission to import
* an endpoint. The <code>export</code> action allows the owner of this
* permission to export a service.
*
* @param filterString The filter string or "*" to match all
* endpoints.
* @param actions The actions <code>read</code>, <code>import</code>, or
* <code>export</code>.
* @throws IllegalArgumentException If the filter has an invalid syntax or
* the actions are not valid.
*/
public EndpointPermission(String filterString, String actions) {
this(filterString, parseActions(actions));
}
/**
* Creates a new requested <code>EndpointPermission</code> object to be used
* by code that must perform <code>checkPermission</code>.
* <code>EndpointPermission</code> objects created with this constructor
* cannot be added to an <code>EndpointPermission</code> permission
* collection.
*
* @param endpoint The requested endpoint.
* @param localFrameworkUUID The UUID of the local framework. This is used
* to support matching the
* {@link RemoteConstants#ENDPOINT_FRAMEWORK_UUID
* endpoint.framework.uuid} endpoint property to the
* <code><<LOCAL>></code> value in the filter expression.
* @param actions The actions <code>read</code>, <code>import</code>, or
* <code>export</code>.
* @throws IllegalArgumentException If the endpoint is <code>null</code> or
* the actions are not valid.
*/
public EndpointPermission(EndpointDescription endpoint,
String localFrameworkUUID, String actions) {
super(createName(endpoint));
setTransients(null, parseActions(actions));
Map<String, Object> props;
if ((localFrameworkUUID != null)
&& localFrameworkUUID.equals(endpoint.getFrameworkUUID())) {
props = new TreeMap<String, Object>(String.CASE_INSENSITIVE_ORDER);
props.putAll(endpoint.getProperties());
props.put(ENDPOINT_FRAMEWORK_UUID, new String[] {
endpoint.getFrameworkUUID(), "<<LOCAL>>"});
}
else {
props = endpoint.getProperties();
}
this.endpoint = endpoint;
this.properties = new EndpointDescription.UnmodifiableDictionary<String, Object>(
props);
}
/**
* Create a permission name from a EndpointDescription.
*
* @param endpoint EndpointDescription to use to create permission name.
* @return permission name.
*/
private static String createName(EndpointDescription endpoint) {
if (endpoint == null) {
throw new IllegalArgumentException("invalid endpoint: null");
}
StringBuffer sb = new StringBuffer("(" + ENDPOINT_ID + "=");
sb.append(endpoint.getId());
sb.append(")");
return sb.toString();
}
/**
* Package private constructor used by EndpointPermissionCollection.
*
* @param name class name
* @param mask action mask
*/
EndpointPermission(String name, int mask) {
super(name);
setTransients(parseFilter(name), mask);
this.endpoint = null;
this.properties = null;
}
/**
* Called by constructors and when deserialized.
*
* @param mask action mask
*/
private void setTransients(Filter f, int mask) {
if ((mask == ACTION_NONE) || ((mask & ACTION_ALL) != mask)) {
throw new IllegalArgumentException("invalid action string");
}
action_mask = mask;
filter = f;
}
/**
* 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 >= 5 && (a[i - 5] == 'i' || a[i - 5] == 'I')
&& (a[i - 4] == 'm' || a[i - 4] == 'M')
&& (a[i - 3] == 'p' || a[i - 3] == 'P')
&& (a[i - 2] == 'o' || a[i - 2] == 'O')
&& (a[i - 1] == 'r' || a[i - 1] == 'R')
&& (a[i] == 't' || a[i] == 'T')) {
matchlen = 6;
mask |= ACTION_IMPORT | ACTION_READ;
}
else
if (i >= 5 && (a[i - 5] == 'e' || a[i - 5] == 'E')
&& (a[i - 4] == 'x' || a[i - 4] == 'X')
&& (a[i - 3] == 'p' || a[i - 3] == 'P')
&& (a[i - 2] == 'o' || a[i - 2] == 'O')
&& (a[i - 1] == 'r' || a[i - 1] == 'R')
&& (a[i] == 't' || a[i] == 'T')) {
matchlen = 6;
mask |= ACTION_EXPORT | ACTION_READ;
}
else {
if (i >= 3 && (a[i - 3] == 'r' || a[i - 3] == 'R')
&& (a[i - 2] == 'e' || a[i - 2] == 'E')
&& (a[i - 1] == 'a' || a[i - 1] == 'A')
&& (a[i] == 'd' || a[i] == 'D')) {
matchlen = 4;
mask |= ACTION_READ;
}
else {
// parse error
throw new IllegalArgumentException(
"invalid permission: " + actions);
}
}
// make sure we didn't just match the tail of a word
// like "ackbarfread". 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 permission: " + 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) {
if (filterString == null) {
throw new IllegalArgumentException("invalid filter: null");
}
filterString = filterString.trim();
if (filterString.equals("*")) {
return null; // wildcard
}
try {
return FrameworkUtil.createFilter(filterString);
}
catch (InvalidSyntaxException e) {
IllegalArgumentException iae = new IllegalArgumentException(
"invalid filter");
iae.initCause(e);
throw iae;
}
}
/**
* Determines if a <code>EndpointPermission</code> object "implies" the
* specified permission.
*
* @param p The target permission to check.
* @return <code>true</code> if the specified permission is implied by this
* object; <code>false</code> otherwise.
*/
public boolean implies(Permission p) {
if (!(p instanceof EndpointPermission)) {
return false;
}
EndpointPermission requested = (EndpointPermission) p;
if (endpoint != 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 EndpointPermission which has already be
* validated as a proper argument. The requested EndpointPermission
* must not have a filter expression.
* @param effective The effective actions with which to start.
* @return <code>true</code> if the specified permission is implied by this
* object; <code>false</code> otherwise.
*/
boolean implies0(EndpointPermission requested, int effective) {
/* check actions first - much faster */
effective |= action_mask;
final int desired = requested.action_mask;
if ((effective & desired) != desired) {
return false;
}
/* if we have no filter */
Filter f = filter;
if (f == null) {
// it's "*"
return true;
}
return f.matchCase(requested.getProperties());
}
/**
* Returns the canonical string representation of the actions. Always
* returns present actions in the following canonical order:
* <code>read</code>, <code>import</code>, <code>export</code>.
*
* @return The canonical string representation of the actions.
*/
public String getActions() {
String result = actions;
if (result == null) {
StringBuffer sb = new StringBuffer();
boolean comma = false;
int mask = action_mask;
if ((mask & ACTION_READ) == ACTION_READ) {
sb.append(READ);
comma = true;
}
if ((mask & ACTION_IMPORT) == ACTION_IMPORT) {
if (comma)
sb.append(',');
sb.append(IMPORT);
}
if ((mask & ACTION_EXPORT) == ACTION_EXPORT) {
if (comma)
sb.append(',');
sb.append(EXPORT);
}
actions = result = sb.toString();
}
return result;
}
/**
* Returns a new <code>PermissionCollection</code> object for storing
* <code>EndpointPermission<code> objects.
*
* @return A new <code>PermissionCollection</code> object suitable for
* storing <code>EndpointPermission</code> objects.
*/
public PermissionCollection newPermissionCollection() {
return new EndpointPermissionCollection();
}
/**
* Determines the equality of two EndpointPermission objects.
*
* Checks that specified object has the same name, actions and endpoint as
* this <code>EndpointPermission</code>.
*
* @param obj The object to test for equality.
* @return true If obj is a <code>EndpointPermission</code>, and has the
* same name, actions and endpoint as this
* <code>EndpointPermission</code> object; <code>false</code>
* otherwise.
*/
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof EndpointPermission)) {
return false;
}
EndpointPermission ep = (EndpointPermission) obj;
return (action_mask == ep.action_mask)
&& getName().equals(ep.getName())
&& ((endpoint == ep.endpoint) || ((endpoint != null)
&& (ep.endpoint != null) && endpoint
.equals(ep.endpoint)));
}
/**
* Returns the hash code value for this object.
*
* @return Hash code value for this object.
*/
public int hashCode() {
int h = 31 * 17 + getName().hashCode();
h = 31 * h + getActions().hashCode();
if (endpoint != null) {
h = 31 * h + endpoint.hashCode();
}
return h;
}
/**
* WriteObject is called to save the state of this permission 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 (endpoint != 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 EndpointPermission#implies(Permission)></code>.
*
* @return a dictionary of properties for this permission.
*/
private Dictionary<String, Object> getProperties() {
return properties;
}
}
/**
* Stores a set of EndpointPermission permissions.
*
* @see java.security.Permission
* @see java.security.Permissions
* @see java.security.PermissionCollection
*/
final class EndpointPermissionCollection extends PermissionCollection {
static final long serialVersionUID = 662615640374640621L;
/**
* Table of permissions.
*
* @serial
* @GuardedBy this
*/
private Map<String, EndpointPermission> permissions;
/**
* Boolean saying if "*" is in the collection.
*
* @serial
* @GuardedBy this
*/
private boolean all_allowed;
/**
* Creates an empty EndpointPermissions object.
*/
public EndpointPermissionCollection() {
permissions = new HashMap<String, EndpointPermission>();
all_allowed = false;
}
/**
* Adds a permission to this permission collection.
*
* @param permission The Permission object to add.
* @throws IllegalArgumentException If the specified permission is not a
* EndpointPermission object.
* @throws SecurityException If this
* <code>EndpointPermissionCollection</code> object has been marked
* read-only.
*/
public void add(final Permission permission) {
if (!(permission instanceof EndpointPermission)) {
throw new IllegalArgumentException("invalid permission: "
+ permission);
}
if (isReadOnly()) {
throw new SecurityException("attempt to add a Permission to a "
+ "readonly PermissionCollection");
}
final EndpointPermission ep = (EndpointPermission) permission;
if (ep.endpoint != null) {
throw new IllegalArgumentException("cannot add to collection: "
+ ep);
}
final String name = ep.getName();
synchronized (this) {
/* select the bucket for the permission */
Map<String, EndpointPermission> pc = permissions;
final EndpointPermission existing = (EndpointPermission) pc
.get(name);
if (existing != null) {
final int oldMask = existing.action_mask;
final int newMask = ep.action_mask;
if (oldMask != newMask) {
pc.put(name,
new EndpointPermission(name, oldMask | newMask));
}
}
else {
pc.put(name, ep);
}
if (!all_allowed) {
if (name.equals("*")) {
all_allowed = true;
}
}
}
}
/**
* Determines if a set of permissions implies the permissions expressed in
* <code>permission</code>.
*
* @param permission The Permission object to compare.
* @return <code>true</code> if <code>permission</code> is a proper subset
* of a permission in the set; <code>false</code> otherwise.
*/
public boolean implies(final Permission permission) {
if (!(permission instanceof EndpointPermission)) {
return false;
}
final EndpointPermission requested = (EndpointPermission) permission;
/* if requested permission has a filter, then it is an invalid argument */
if (requested.filter != null) {
return false;
}
int effective = EndpointPermission.ACTION_NONE;
Collection<EndpointPermission> perms;
synchronized (this) {
final int desired = requested.action_mask;
/* short circuit if the "*" Permission was added */
if (all_allowed) {
EndpointPermission ep = permissions.get("*");
if (ep != null) {
effective |= ep.action_mask;
if ((effective & desired) == desired) {
return true;
}
}
}
perms = permissions.values();
}
/* iterate one by one over permissions */
for (Iterator<EndpointPermission> iter = perms.iterator(); iter
.hasNext();) {
if (iter.next().implies0(requested, effective)) {
return true;
}
}
return false;
}
/**
* Returns an enumeration of all the <code>EndpointPermission</code> objects
* in the container.
*
* @return Enumeration of all the EndpointPermission 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, EndpointPermission>) gfields.get(
"permissions", new HashMap<String, EndpointPermission>());
all_allowed = gfields.get("all_allowed", false);
}
}