/*
* Copyright (c) OSGi Alliance (2000, 2013). 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.subsystem;
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;
import org.osgi.framework.Filter;
import org.osgi.framework.FrameworkUtil;
import org.osgi.framework.InvalidSyntaxException;
/**
* A bundle's authority to perform specific privileged administrative operations
* on or to get sensitive information about a subsystem. The actions for this
* permission are:
*
* <pre>
* Action Methods
* context Subsystem.getBundleContext
* execute Subsystem.start
* Subsystem.stop
* lifecycle Subsystem.install
* Subsystem.uninstall
* metadata Subsystem.getSubsystemHeaders
* Subsystem.getLocation
* </pre>
*
* <p>
* The name of this permission is a filter expression. The filter gives access
* to the following attributes:
* <ul>
* <li>location - The location of a subsystem.</li>
* <li>id - The subsystem ID of the designated subsystem.</li>
* <li>name - The symbolic name of a subsystem.</li>
* </ul>
* Filter attribute names are processed in a case sensitive manner.
*
* @ThreadSafe
* @author $Id: 5c71d73cc6a3e8b2c2a7a3f188ebcf79b5ef7888 $
*/
public final class SubsystemPermission extends BasicPermission {
static final long serialVersionUID = 307051004521261705L;
/**
* The action string {@code execute}.
*/
public final static String EXECUTE = "execute";
/**
* The action string {@code lifecycle}.
*/
public final static String LIFECYCLE = "lifecycle";
/**
* The action string {@code metadata}.
*/
public final static String METADATA = "metadata";
/**
* The action string {@code context}.
*/
public final static String CONTEXT = "context";
private final static int ACTION_EXECUTE = 0x00000001;
private final static int ACTION_LIFECYCLE = 0x00000002;
private final static int ACTION_METADATA = 0x00000004;
private final static int ACTION_CONTEXT = 0x00000008;
private final static int ACTION_ALL = ACTION_EXECUTE | ACTION_LIFECYCLE | ACTION_METADATA | ACTION_CONTEXT;
final static int ACTION_NONE = 0;
/**
* The actions in canonical form.
*
* @serial
*/
private volatile String actions = null;
/**
* The actions mask.
*/
transient int action_mask;
/**
* If this SubsystemPermission was constructed with a filter, this holds a
* Filter matching object used to evaluate the filter in implies.
*/
transient Filter filter;
/**
* The subsystem governed by this SubsystemPermission - only used if filter
* == null
*/
transient final Subsystem subsystem;
/**
* 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;
/**
* ThreadLocal used to determine if we have recursively called
* getProperties.
*/
private static final ThreadLocal<Subsystem> recurse = new ThreadLocal<Subsystem>();
/**
* Create a new SubsystemPermission.
*
* This constructor must only be used to create a permission that is going
* to be checked.
* <p>
* Examples:
*
* <pre>
* (name=com.acme.*)(location=http://www.acme.com/subsystems/*))
* (id>=1)
* </pre>
*
* @param filter A filter expression that can use, location, id, and name
* keys. Filter attribute names are processed in a case sensitive
* manner. A special value of {@code "*"} can be used to match all
* subsystems.
* @param actions {@code execute}, {@code lifecycle}, {@code metadata}, or
* {@code context}.
* @throws IllegalArgumentException If the filter has an invalid syntax.
*/
public SubsystemPermission(String filter, String actions) {
this(parseFilter(filter), parseActions(actions));
}
/**
* Creates a new requested {@code SubsystemPermission} object to be used by
* the code that must perform {@code checkPermission}.
* {@code SubsystemPermission} objects created with this constructor cannot
* be added to an {@code SubsystemPermission} permission collection.
*
* @param subsystem A subsystem.
* @param actions {@code execute}, {@code lifecycle}, {@code metadata}, or
* {@code context}.
*/
public SubsystemPermission(Subsystem subsystem, String actions) {
super(createName(subsystem));
setTransients(null, parseActions(actions));
this.subsystem = subsystem;
}
/**
* Create a permission name from a Subsystem
*
* @param subsystem Subsystem to use to create permission name.
* @return permission name.
*/
private static String createName(Subsystem subsystem) {
if (subsystem == null) {
throw new IllegalArgumentException("subsystem must not be null");
}
StringBuffer sb = new StringBuffer("(id=");
sb.append(subsystem.getSubsystemId());
sb.append(")");
return sb.toString();
}
/**
* Package private constructor used by SubsystemPermissionCollection.
*
* @param filter name filter or {@code null} for wildcard.
* @param mask action mask
*/
SubsystemPermission(Filter filter, int mask) {
super((filter == null) ? "*" : filter.toString());
setTransients(filter, mask);
this.subsystem = 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 >= 6 && (a[i - 6] == 'e' || a[i - 6] == 'E')
&& (a[i - 5] == 'x' || a[i - 5] == 'X')
&& (a[i - 4] == 'e' || a[i - 4] == 'E')
&& (a[i - 3] == 'c' || a[i - 3] == 'C')
&& (a[i - 2] == 'u' || a[i - 2] == 'U')
&& (a[i - 1] == 't' || a[i - 1] == 'T')
&& (a[i] == 'e' || a[i] == 'E')) {
matchlen = 7;
mask |= ACTION_EXECUTE;
} else
if (i >= 8 && (a[i - 8] == 'l' || a[i - 8] == 'L')
&& (a[i - 7] == 'i' || a[i - 7] == 'I')
&& (a[i - 6] == 'f' || a[i - 6] == 'F')
&& (a[i - 5] == 'e' || a[i - 5] == 'E')
&& (a[i - 4] == 'c' || a[i - 4] == 'C')
&& (a[i - 3] == 'y' || a[i - 3] == 'Y')
&& (a[i - 2] == 'c' || a[i - 2] == 'C')
&& (a[i - 1] == 'l' || a[i - 1] == 'L')
&& (a[i] == 'e' || a[i] == 'E')) {
matchlen = 9;
mask |= ACTION_LIFECYCLE;
} else
if (i >= 7
&& (a[i - 7] == 'm' || a[i - 7] == 'M')
&& (a[i - 6] == 'e' || a[i - 6] == 'E')
&& (a[i - 5] == 't' || a[i - 5] == 'T')
&& (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] == 't' || a[i - 1] == 'T')
&& (a[i] == 'a' || a[i] == 'A')) {
matchlen = 8;
mask |= ACTION_METADATA;
} else
if (i >= 6
&& (a[i - 6] == 'c' || a[i - 6] == 'C')
&& (a[i - 5] == 'o' || a[i - 5] == 'O')
&& (a[i - 4] == 'n' || a[i - 4] == 'N')
&& (a[i - 3] == 't' || a[i - 3] == 'T')
&& (a[i - 2] == 'e' || a[i - 2] == 'E')
&& (a[i - 1] == 'x' || a[i - 1] == 'X')
&& (a[i] == 't' || a[i] == 'T')) {
matchlen = 7;
mask |= ACTION_CONTEXT;
} else {
// parse error
throw new IllegalArgumentException("invalid permission: " + actions);
}
// make sure we didn't just match the tail of a word
// like "ackbarfexecute". 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 subsystem. If the specified filterString equals
* "*", then {@code null} is returned to indicate a wildcard.
* @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. This
* method throws an exception if the specified permission was not
* constructed with a subsystem.
*
* <p>
* This method returns {@code true} if the specified permission is a
* SubsystemPermission AND
* <ul>
* <li>this object's filter matches the specified permission's subsystem ID,
* subsystem symbolic name, and subsystem location OR</li>
* <li>this object's filter is "*"</li>
* </ul>
* AND this object's actions include all of the specified permission's
* actions.
* <p>
* Special case: if the specified permission was constructed with "*"
* filter, then this method returns {@code true} if this object's filter is
* "*" and this object's actions include all of the specified permission's
* actions
*
* @param p The requested permission.
* @return {@code true} if the specified permission is implied by this
* object; {@code false} otherwise.
*/
@Override
public boolean implies(Permission p) {
if (!(p instanceof SubsystemPermission)) {
return false;
}
SubsystemPermission requested = (SubsystemPermission) p;
if (subsystem != 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 SubsystemPermision which has already been
* validated as a proper argument. The requested SubsystemPermission
* 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(SubsystemPermission requested, int effective) {
/* check actions first - much faster */
effective |= action_mask;
final int desired = requested.action_mask;
if ((effective & desired) != desired) {
return false;
}
/* Get our filter */
Filter f = filter;
if (f == null) {
// it's "*"
return true;
}
/* is requested a wildcard filter? */
if (requested.subsystem == null) {
return false;
}
Map<String, Object> requestedProperties = requested.getProperties();
if (requestedProperties == null) {
/*
* If the requested properties are null, then we have detected a
* recursion getting the subsystem location. So we return true to
* permit the subsystem location request in the SubsystemPermission
* check up the stack to succeed.
*/
return true;
}
return f.matches(requestedProperties);
}
/**
* Returns the canonical string representation of the
* {@code SubsystemPermission} actions.
*
* <p>
* Always returns present {@code SubsystemPermission} actions in the
* following order: {@code execute}, {@code lifecycle}, {@code metadata},
* {@code context}.
*
* @return Canonical string representation of the
* {@code SubsystemPermission} actions.
*/
@Override
public String getActions() {
String result = actions;
if (result == null) {
StringBuffer sb = new StringBuffer();
int mask = action_mask;
if ((mask & ACTION_EXECUTE) == ACTION_EXECUTE) {
sb.append(EXECUTE);
sb.append(',');
}
if ((mask & ACTION_LIFECYCLE) == ACTION_LIFECYCLE) {
sb.append(LIFECYCLE);
sb.append(',');
}
if ((mask & ACTION_METADATA) == ACTION_METADATA) {
sb.append(METADATA);
sb.append(',');
}
if ((mask & ACTION_CONTEXT) == ACTION_CONTEXT) {
sb.append(CONTEXT);
sb.append(',');
}
// remove trailing comma
if (sb.length() > 0) {
sb.setLength(sb.length() - 1);
}
actions = result = sb.toString();
}
return result;
}
/**
* Returns a new {@code PermissionCollection} object suitable for storing
* {@code SubsystemPermission}s.
*
* @return A new {@code PermissionCollection} object.
*/
@Override
public PermissionCollection newPermissionCollection() {
return new SubsystemPermissionCollection();
}
/**
* Determines the equality of two {@code SubsystemPermission} objects.
*
* @param obj The object being compared for equality with this object.
* @return {@code true} if {@code obj} is equivalent to this
* {@code SubsystemPermission}; {@code false} otherwise.
*/
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof SubsystemPermission)) {
return false;
}
SubsystemPermission sp = (SubsystemPermission) obj;
return (action_mask == sp.action_mask) && ((subsystem == sp.subsystem) || ((subsystem != null) && subsystem.equals(sp.subsystem)))
&& (filter == null ? sp.filter == null : filter.equals(sp.filter));
}
/**
* Returns the hash code value for this object.
*
* @return Hash code value for this object.
*/
@Override
public int hashCode() {
int h = 31 * 17 + getName().hashCode();
h = 31 * h + getActions().hashCode();
if (subsystem != null) {
h = 31 * h + subsystem.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 (subsystem != 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 data, then initialize the transients
s.defaultReadObject();
setTransients(parseFilter(getName()), parseActions(actions));
}
/**
* Called by {@code implies0} on an SubsystemPermission which was
* constructed with a Subsystem. This method loads a map with the
* filter-matchable properties of this subsystem. The map is cached so this
* lookup only happens once.
*
* This method should only be called on an SubsystemPermission which was
* constructed with a subsystem
*
* @return a map of properties for this subsystem
*/
private Map<String, Object> getProperties() {
Map<String, Object> result = properties;
if (result != null) {
return result;
}
/*
* We may have recursed here due to the Subsystem.getLocation call in
* the doPrivileged below. If this is the case, return null to allow
* implies to return true.
*/
final Object mark = recurse.get();
if (mark == subsystem) {
return null;
}
recurse.set(subsystem);
try {
final Map<String, Object> map = new HashMap<String, Object>(4);
AccessController.doPrivileged(new PrivilegedAction<Void>() {
public Void run() {
map.put("id", new Long(subsystem.getSubsystemId()));
map.put("location", subsystem.getLocation());
map.put("name", subsystem.getSymbolicName());
return null;
}
});
return properties = map;
} finally {
recurse.set(null);
}
}
}
/**
* Stores a collection of {@code SubsystemPermission}s.
*/
final class SubsystemPermissionCollection extends PermissionCollection {
private static final long serialVersionUID = 3906372644575328048L;
/**
* Collection of permissions.
*
* @GuardedBy this
*/
private transient Map<String, SubsystemPermission> permissions;
/**
* Boolean saying if "*" is in the collection.
*
* @serial
* @GuardedBy this
*/
private boolean all_allowed;
/**
* Create an empty SubsystemPermissionCollection object.
*
*/
public SubsystemPermissionCollection() {
permissions = new HashMap<String, SubsystemPermission>();
}
/**
* Adds a permission to this permission collection.
*
* @param permission The {@code SubsystemPermission} object to add.
* @throws IllegalArgumentException If the specified permission is not an
* {@code SubsystemPermission} instance or was constructed with a
* Subsystem object.
* @throws SecurityException If this {@code SubsystemPermissionCollection}
* object has been marked read-only.
*/
@Override
public void add(Permission permission) {
if (!(permission instanceof SubsystemPermission)) {
throw new IllegalArgumentException("invalid permission: " + permission);
}
if (isReadOnly()) {
throw new SecurityException("attempt to add a Permission to a " + "readonly PermissionCollection");
}
final SubsystemPermission sp = (SubsystemPermission) permission;
if (sp.subsystem != null) {
throw new IllegalArgumentException("cannot add to collection: " + sp);
}
final String name = sp.getName();
synchronized (this) {
Map<String, SubsystemPermission> pc = permissions;
SubsystemPermission existing = pc.get(name);
if (existing != null) {
int oldMask = existing.action_mask;
int newMask = sp.action_mask;
if (oldMask != newMask) {
pc.put(name, new SubsystemPermission(existing.filter, oldMask | newMask));
}
} else {
pc.put(name, sp);
}
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 the
* {@code SubsystemPermission} objects in this collection.
* @return {@code true} if {@code permission} is implied by an
* {@code SubsystemPermission} in this collection, {@code false}
* otherwise.
*/
@Override
public boolean implies(Permission permission) {
if (!(permission instanceof SubsystemPermission)) {
return false;
}
SubsystemPermission requested = (SubsystemPermission) permission;
// if requested permission has a filter, then it is an invalid argument
if (requested.filter != null) {
return false;
}
int effective = SubsystemPermission.ACTION_NONE;
Collection<SubsystemPermission> perms;
synchronized (this) {
Map<String, SubsystemPermission> pc = permissions;
// short circuit if the "*" Permission was added
if (all_allowed) {
SubsystemPermission sp = pc.get("*");
if (sp != null) {
effective |= sp.action_mask;
final int desired = requested.action_mask;
if ((effective & desired) == desired) {
return true;
}
}
}
perms = pc.values();
}
// just iterate one by one
for (SubsystemPermission perm : perms) {
if (perm.implies0(requested, effective)) {
return true;
}
}
return false;
}
/**
* Returns an enumeration of all {@code SubsystemPermission} objects in the
* container.
*
* @return Enumeration of all {@code SubsystemPermission} objects.
*/
@Override
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();
@SuppressWarnings("unchecked")
HashMap<String, SubsystemPermission> p = (HashMap<String, SubsystemPermission>) gfields.get("permissions", null);
permissions = p;
all_allowed = gfields.get("all_allowed", false);
}
}