/*
* Copyright (c) OSGi Alliance (2004, 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.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamField;
import java.security.BasicPermission;
import java.security.Permission;
import java.security.PermissionCollection;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.List;
import java.util.Map;
/**
* A bundle's authority to require or provide a bundle or to receive or attach
* fragments.
*
* <p>
* A bundle symbolic name defines a unique fully qualified name. Wildcards may
* be used.
*
* <pre>
* name ::= <symbolic name> | <symbolic name ending in ".*"> | *
* </pre>
*
* Examples:
*
* <pre>
* org.osgi.example.bundle
* org.osgi.example.*
* *
* </pre>
*
* <p>
* {@code BundlePermission} has four actions: {@code provide}, {@code require},
* {@code host}, and {@code fragment}. The {@code provide} action implies the
* {@code require} action.
*
* @since 1.3
* @ThreadSafe
* @version $Id: ccba905e3373800dfdb080118e97145abf778da2 $
*/
public final class BundlePermission extends BasicPermission {
private static final long serialVersionUID = 3257846601685873716L;
/**
* The action string {@code provide}. The {@code provide} action implies the
* {@code require} action.
*/
public final static String PROVIDE = "provide";
/**
* The action string {@code require}. The {@code require} action is implied
* by the {@code provide} action.
*/
public final static String REQUIRE = "require";
/**
* The action string {@code host}.
*/
public final static String HOST = "host";
/**
* The action string {@code fragment}.
*/
public final static String FRAGMENT = "fragment";
private final static int ACTION_PROVIDE = 0x00000001;
private final static int ACTION_REQUIRE = 0x00000002;
private final static int ACTION_HOST = 0x00000004;
private final static int ACTION_FRAGMENT = 0x00000008;
private final static int ACTION_ALL = ACTION_PROVIDE | ACTION_REQUIRE | ACTION_HOST | ACTION_FRAGMENT;
final static int ACTION_NONE = 0;
/**
* The actions mask.
*/
private transient int action_mask;
/**
* The actions in canonical form.
*
* @serial
*/
private volatile String actions = null;
/**
* Defines the authority to provide and/or require and or specify a host
* fragment symbolic name within the OSGi environment.
* <p>
* Bundle Permissions are granted over all possible versions of a bundle.
*
* A bundle that needs to provide a bundle must have the appropriate
* {@code BundlePermission} for the symbolic name; a bundle that requires a
* bundle must have the appropriate {@code BundlePermssion} for that
* symbolic name; a bundle that specifies a fragment host must have the
* appropriate {@code BundlePermission} for that symbolic name.
*
* @param symbolicName The bundle symbolic name.
* @param actions {@code provide},{@code require}, {@code host},
* {@code fragment} (canonical order).
*/
public BundlePermission(String symbolicName, String actions) {
this(symbolicName, parseActions(actions));
}
/**
* Package private constructor used by BundlePermissionCollection.
*
* @param symbolicName the bundle symbolic name
* @param mask the action mask
*/
BundlePermission(String symbolicName, int mask) {
super(symbolicName);
setTransients(mask);
}
/**
* Called by constructors and when deserialized.
*
* @param mask
*/
private synchronized void setTransients(int mask) {
if ((mask == ACTION_NONE) || ((mask & ACTION_ALL) != mask)) {
throw new IllegalArgumentException("invalid action string");
}
action_mask = mask;
}
/**
* Returns the current action mask.
* <p>
* Used by the BundlePermissionCollection class.
*
* @return Current action mask.
*/
synchronized int getActionsMask() {
return action_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 >= 6 && (a[i - 6] == 'p' || a[i - 6] == 'P')
&& (a[i - 5] == 'r' || a[i - 5] == 'R')
&& (a[i - 4] == 'o' || a[i - 4] == 'O')
&& (a[i - 3] == 'v' || a[i - 3] == 'V')
&& (a[i - 2] == 'i' || a[i - 2] == 'I')
&& (a[i - 1] == 'd' || a[i - 1] == 'D')
&& (a[i] == 'e' || a[i] == 'E')) {
matchlen = 7;
mask |= ACTION_PROVIDE | ACTION_REQUIRE;
} else
if (i >= 6 && (a[i - 6] == 'r' || a[i - 6] == 'R')
&& (a[i - 5] == 'e' || a[i - 5] == 'E')
&& (a[i - 4] == 'q' || a[i - 4] == 'Q')
&& (a[i - 3] == 'u' || a[i - 3] == 'U')
&& (a[i - 2] == 'i' || a[i - 2] == 'I')
&& (a[i - 1] == 'r' || a[i - 1] == 'R')
&& (a[i] == 'e' || a[i] == 'E')) {
matchlen = 7;
mask |= ACTION_REQUIRE;
} else
if (i >= 3 && (a[i - 3] == 'h' || a[i - 3] == 'H')
&& (a[i - 2] == 'o' || a[i - 2] == 'O')
&& (a[i - 1] == 's' || a[i - 1] == 'S')
&& (a[i] == 't' || a[i] == 'T')) {
matchlen = 4;
mask |= ACTION_HOST;
} else
if (i >= 7 && (a[i - 7] == 'f' || a[i - 7] == 'F')
&& (a[i - 6] == 'r' || a[i - 6] == 'R')
&& (a[i - 5] == 'a' || a[i - 5] == 'A')
&& (a[i - 4] == 'g' || a[i - 4] == 'G')
&& (a[i - 3] == 'm' || a[i - 3] == 'M')
&& (a[i - 2] == 'e' || a[i - 2] == 'E')
&& (a[i - 1] == 'n' || a[i - 1] == 'N')
&& (a[i] == 't' || a[i] == 'T')) {
matchlen = 8;
mask |= ACTION_FRAGMENT;
} else {
// parse error
throw new IllegalArgumentException("invalid permission: " + actions);
}
// make sure we didn't just match the tail of a word
// like "ackbarfrequire". 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;
}
/**
* Determines if the specified permission is implied by this object.
*
* <p>
* This method checks that the symbolic name of the target is implied by the
* symbolic name of this object. The list of {@code BundlePermission}
* actions must either match or allow for the list of the target object to
* imply the target {@code BundlePermission} action.
* <p>
* The permission to provide a bundle implies the permission to require the
* named symbolic name.
*
* <pre>
* x.y.*,"provide" -> x.y.z,"provide" is true
* *,"require" -> x.y, "require" is true
* *,"provide" -> x.y, "require" is true
* x.y,"provide" -> x.y.z, "provide" is false
* </pre>
*
* @param p The requested permission.
* @return {@code true} if the specified {@code BundlePermission} action is
* implied by this object; {@code false} otherwise.
*/
public boolean implies(Permission p) {
if (!(p instanceof BundlePermission)) {
return false;
}
BundlePermission requested = (BundlePermission) p;
final int effective = getActionsMask();
final int desired = requested.getActionsMask();
return ((effective & desired) == desired) && super.implies(requested);
}
/**
* Returns the canonical string representation of the
* {@code BundlePermission} actions.
*
* <p>
* Always returns present {@code BundlePermission} actions in the following
* order: {@code provide}, {@code require}, {@code host}, {@code fragment}.
*
* @return Canonical string representation of the {@code BundlePermission
* } actions.
*/
public String getActions() {
String result = actions;
if (result == null) {
StringBuffer sb = new StringBuffer();
boolean comma = false;
if ((action_mask & ACTION_PROVIDE) == ACTION_PROVIDE) {
sb.append(PROVIDE);
comma = true;
}
if ((action_mask & ACTION_REQUIRE) == ACTION_REQUIRE) {
if (comma)
sb.append(',');
sb.append(REQUIRE);
comma = true;
}
if ((action_mask & ACTION_HOST) == ACTION_HOST) {
if (comma)
sb.append(',');
sb.append(HOST);
comma = true;
}
if ((action_mask & ACTION_FRAGMENT) == ACTION_FRAGMENT) {
if (comma)
sb.append(',');
sb.append(FRAGMENT);
}
actions = result = sb.toString();
}
return result;
}
/**
* Returns a new {@code PermissionCollection} object suitable for storing
* {@code BundlePermission} objects.
*
* @return A new {@code PermissionCollection} object.
*/
public PermissionCollection newPermissionCollection() {
return new BundlePermissionCollection();
}
/**
* Determines the equality of two {@code BundlePermission} objects.
*
* This method checks that specified bundle has the same bundle symbolic
* name and {@code BundlePermission} actions as this
* {@code BundlePermission} object.
*
* @param obj The object to test for equality with this
* {@code BundlePermission} object.
* @return {@code true} if {@code obj} is a {@code BundlePermission}, and
* has the same bundle symbolic name and actions as this
* {@code BundlePermission} object; {@code false} otherwise.
*/
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof BundlePermission)) {
return false;
}
BundlePermission bp = (BundlePermission) obj;
return (getActionsMask() == bp.getActionsMask()) && getName().equals(bp.getName());
}
/**
* 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();
return h;
}
/**
* WriteObject is called to save the state of the {@code BundlePermission}
* 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 {
// 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 the BundlePermission 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(parseActions(actions));
}
}
/**
* Stores a set of {@code BundlePermission} permissions.
*
* @see java.security.Permission
* @see java.security.Permissions
* @see java.security.PermissionCollection
*/
final class BundlePermissionCollection extends PermissionCollection {
private static final long serialVersionUID = 3258407326846433079L;
/**
* Table of permissions.
*
* @GuardedBy this
*/
private transient Map<String, BundlePermission> permissions;
/**
* Boolean saying if "*" is in the collection.
*
* @serial
* @GuardedBy this
*/
private boolean all_allowed;
/**
* Create an empty BundlePermissions object.
*
*/
public BundlePermissionCollection() {
permissions = new HashMap<String, BundlePermission>();
all_allowed = false;
}
/**
* Add a permission to this permission collection.
*
* @param permission The {@code BundlePermission} object to add.
* @throws IllegalArgumentException If the permission is not a
* {@code BundlePermission} instance.
* @throws SecurityException If this {@code BundlePermissionCollection}
* object has been marked read-only.
*/
public void add(final Permission permission) {
if (!(permission instanceof BundlePermission)) {
throw new IllegalArgumentException("invalid permission: " + permission);
}
if (isReadOnly()) {
throw new SecurityException("attempt to add a Permission to a " + "readonly PermissionCollection");
}
final BundlePermission bp = (BundlePermission) permission;
final String name = bp.getName();
synchronized (this) {
Map<String, BundlePermission> pc = permissions;
BundlePermission existing = pc.get(name);
if (existing != null) {
final int oldMask = existing.getActionsMask();
final int newMask = bp.getActionsMask();
if (oldMask != newMask) {
pc.put(name, new BundlePermission(name, oldMask | newMask));
}
} else {
pc.put(name, bp);
}
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 BundlePermission} 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 BundlePermission)) {
return false;
}
BundlePermission requested = (BundlePermission) permission;
String requestedName = requested.getName();
final int desired = requested.getActionsMask();
int effective = BundlePermission.ACTION_NONE;
BundlePermission bp;
synchronized (this) {
Map<String, BundlePermission> pc = permissions;
/* short circuit if the "*" Permission was added */
if (all_allowed) {
bp = pc.get("*");
if (bp != null) {
effective |= bp.getActionsMask();
if ((effective & desired) == desired) {
return true;
}
}
}
bp = pc.get(requestedName);
// strategy:
// Check for full match first. Then work our way up the
// name looking for matches on a.b.*
if (bp != null) {
// we have a direct hit!
effective |= bp.getActionsMask();
if ((effective & desired) == desired) {
return true;
}
}
// work our way up the tree...
int last;
int offset = requestedName.length() - 1;
while ((last = requestedName.lastIndexOf(".", offset)) != -1) {
requestedName = requestedName.substring(0, last + 1) + "*";
bp = pc.get(requestedName);
if (bp != null) {
effective |= bp.getActionsMask();
if ((effective & desired) == desired) {
return true;
}
}
offset = last - 1;
}
// we don't have to check for "*" as it was already checked
// at the top (all_allowed), so we just return false
return false;
}
}
/**
* Returns an enumeration of all {@code BundlePermission} objects in the
* container.
*
* @return Enumeration of all {@code BundlePermission} 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", Hashtable.class), new ObjectStreamField("all_allowed", Boolean.TYPE)};
private synchronized void writeObject(ObjectOutputStream out) throws IOException {
Hashtable<String, BundlePermission> hashtable = new Hashtable<String, BundlePermission>(permissions);
ObjectOutputStream.PutField pfields = out.putFields();
pfields.put("permissions", hashtable);
pfields.put("all_allowed", all_allowed);
out.writeFields();
}
private synchronized void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException {
ObjectInputStream.GetField gfields = in.readFields();
Hashtable<String, BundlePermission> hashtable = (Hashtable<String, BundlePermission>) gfields.get("permissions", null);
permissions = new HashMap<String, BundlePermission>(hashtable);
all_allowed = gfields.get("all_allowed", false);
}
}