/*
* Copyright (c) OSGi Alliance (2000, 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.AbstractMap;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* A bundle's authority to provide or require a capability.
* <ul>
* <li>The {@code provide} action allows a bundle to provide a capability
* matching the specified filter.
* <li>The {@code require} action allows a bundle to require a capability
* matching the specified filter.
* </ul>
*
* @ThreadSafe
* @version $Id: b17bcaec959f67c3eae4c4c80c39a0a8716b22dc $
* @since 1.6
*/
public final class CapabilityPermission extends BasicPermission {
static final long serialVersionUID = -7662148639076511574L;
/**
* The action string {@code require}.
*/
public final static String REQUIRE = "require";
/**
* The action string {@code provide}.
*/
public final static String PROVIDE = "provide";
private final static int ACTION_REQUIRE = 0x00000001;
private final static int ACTION_PROVIDE = 0x00000002;
private final static int ACTION_ALL = ACTION_REQUIRE | ACTION_PROVIDE;
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 attributes of the requested capability. Must be null if not
* constructed with attributes.
*/
transient final Map<String, Object> attributes;
/**
* The bundle of the requested capability. Must be null if not constructed
* with bundle.
*/
transient final Bundle bundle;
/**
* If this CapabilityPermission was constructed with a filter, 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;
/**
* Create a new CapabilityPermission.
*
* <p>
* The name is specified as a dot-separated string. Wildcards may be used.
*
* <pre>
* name ::= <namespace> | <namespace ending in ".*"> | *
* </pre>
*
* Examples:
*
* <pre>
* com.acme.capability.*
* org.foo.capability
* *
* </pre>
*
* For the {@code require} action, the name can also be a filter expression.
* The filter gives access to the capability attributes as well as the
* following attributes:
* <ul>
* <li>signer - A Distinguished Name chain used to sign the bundle providing
* the capability. 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 bundle providing the capability.</li>
* <li>id - The bundle ID of the bundle providing the capability.</li>
* <li>name - The symbolic name of the bundle providing the capability.</li>
* <li>capability.namespace - The namespace of the required capability.</li>
* </ul>
* Since the above attribute names may conflict with attribute names of a
* capability, you can prefix an attribute name with '@' in the filter
* expression to match against the capability attributes and not one of the
* above attributes. Filter attribute names are processed in a case
* sensitive manner.
*
* <p>
* There are two possible actions: {@code require} and {@code provide}. The
* {@code require} permission allows the owner of this permission to require
* a capability matching the attributes. The {@code provide} permission
* allows the bundle to provide a capability in the specified capability
* namespace.
*
* @param name The capability namespace or a filter over the attributes.
* @param actions {@code require},{@code provide} (canonical order)
* @throws IllegalArgumentException If the specified name is a filter
* expression and either the specified action is not {@code require}
* or the filter has an invalid syntax.
*/
public CapabilityPermission(String name, String actions) {
this(name, parseActions(actions));
if ((this.filter != null) && ((action_mask & ACTION_ALL) != ACTION_REQUIRE)) {
throw new IllegalArgumentException("invalid action string for filter expression");
}
}
/**
* Creates a new requested {@code CapabilityPermission} object to be used by
* code that must perform {@code checkPermission} for the {@code require}
* action. {@code CapabilityPermission} objects created with this
* constructor cannot be added to a {@code CapabilityPermission} permission
* collection.
*
* @param namespace The requested capability namespace.
* @param attributes The requested capability attributes.
* @param providingBundle The bundle providing the requested capability.
* @param actions The action {@code require}.
* @throws IllegalArgumentException If the specified action is not
* {@code require} or attributes or providingBundle are {@code null}
* .
*/
public CapabilityPermission(String namespace, Map<String, ?> attributes, Bundle providingBundle, String actions) {
super(namespace);
setTransients(namespace, parseActions(actions));
if (attributes == null) {
throw new IllegalArgumentException("attributes must not be null");
}
if (providingBundle == null) {
throw new IllegalArgumentException("bundle must not be null");
}
this.attributes = new HashMap<String, Object>(attributes);
this.bundle = providingBundle;
if ((action_mask & ACTION_ALL) != ACTION_REQUIRE) {
throw new IllegalArgumentException("invalid action string");
}
}
/**
* Package private constructor used by CapabilityPermissionCollection.
*
* @param name class name
* @param mask action mask
*/
CapabilityPermission(String name, int mask) {
super(name);
setTransients(name, mask);
this.attributes = null;
this.bundle = null;
}
/**
* Called by constructors and when deserialized.
*
* @param mask action mask
*/
private void setTransients(String name, int mask) {
if ((mask == ACTION_NONE) || ((mask & ACTION_ALL) != mask)) {
throw new IllegalArgumentException("invalid action string");
}
action_mask = mask;
filter = parseFilter(name);
}
/**
* 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] == '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 >= 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;
} else {
// parse error
throw new IllegalArgumentException("invalid permission: " + actions);
}
// make sure we didn't just match the tail of a word
// like "ackbarfprovide". 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. If the specified filterString is not a
* filter expression, then {@code null} is returned.
* @throws IllegalArgumentException If the filter syntax is invalid.
*/
private static Filter parseFilter(String filterString) {
filterString = filterString.trim();
if (filterString.charAt(0) != '(') {
return null;
}
try {
return FrameworkUtil.createFilter(filterString);
} catch (InvalidSyntaxException e) {
IllegalArgumentException iae = new IllegalArgumentException("invalid filter");
iae.initCause(e);
throw iae;
}
}
/**
* Determines if a {@code CapabilityPermission} object "implies" the
* specified permission.
*
* @param p The target permission to check.
* @return {@code true} if the specified permission is implied by this
* object; {@code false} otherwise.
*/
public boolean implies(Permission p) {
if (!(p instanceof CapabilityPermission)) {
return false;
}
CapabilityPermission requested = (CapabilityPermission) 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 CapabilityPermission which has already be
* validated as a proper argument. The requested CapabilityPermission
* 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(CapabilityPermission 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 if any */
Filter f = filter;
if (f == null) {
return super.implies(requested);
}
return f.matches(requested.getProperties());
}
/**
* Returns the canonical string representation of the actions. Always
* returns present actions in the following order: {@code require},
* {@code provide}.
*
* @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_REQUIRE) == ACTION_REQUIRE) {
sb.append(REQUIRE);
comma = true;
}
if ((mask & ACTION_PROVIDE) == ACTION_PROVIDE) {
if (comma)
sb.append(',');
sb.append(PROVIDE);
}
actions = result = sb.toString();
}
return result;
}
/**
* Returns a new {@code PermissionCollection} object for storing
* {@code CapabilityPermission} objects.
*
* @return A new {@code PermissionCollection} object suitable for storing
* {@code CapabilityPermission} objects.
*/
public PermissionCollection newPermissionCollection() {
return new CapabilityPermissionCollection();
}
/**
* Determines the equality of two CapabilityPermission objects.
*
* Checks that specified object has the same name and action as this
* {@code CapabilityPermission}.
*
* @param obj The object to test for equality.
* @return true if obj is a {@code CapabilityPermission}, and has the same
* name and actions as this {@code CapabilityPermission} object;
* {@code false} otherwise.
*/
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof CapabilityPermission)) {
return false;
}
CapabilityPermission cp = (CapabilityPermission) obj;
return (action_mask == cp.action_mask) && getName().equals(cp.getName()) && ((attributes == cp.attributes) || ((attributes != null) && (attributes.equals(cp.attributes))))
&& ((bundle == cp.bundle) || ((bundle != null) && bundle.equals(cp.bundle)));
}
/**
* 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 (attributes != null) {
h = 31 * h + attributes.hashCode();
}
if (bundle != null) {
h = 31 * h + bundle.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 (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(getName(), parseActions(actions));
}
/**
* Called by {@code <@link CapabilityPermission#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> props = new HashMap<String, Object>(5);
props.put("capability.namespace", getName());
if (bundle == null) {
return properties = props;
}
AccessController.doPrivileged(new PrivilegedAction<Object>() {
public Object run() {
props.put("id", new Long(bundle.getBundleId()));
props.put("location", bundle.getLocation());
String name = bundle.getSymbolicName();
if (name != null) {
props.put("name", name);
}
SignerProperty signer = new SignerProperty(bundle);
if (signer.isBundleSigned()) {
props.put("signer", signer);
}
return null;
}
});
return properties = new Properties(props, attributes);
}
static private final class Properties extends AbstractMap<String, Object> {
private final Map<String, Object> properties;
private final Map<String, Object> attributes;
private transient volatile Set<Map.Entry<String, Object>> entries;
Properties(Map<String, Object> properties, Map<String, Object> attributes) {
this.properties = properties;
this.attributes = attributes;
entries = null;
}
public Object get(Object k) {
if (!(k instanceof String)) {
return null;
}
String key = (String) k;
if (key.charAt(0) == '@') {
return attributes.get(key.substring(1));
}
Object value = properties.get(key);
if (value != null) { // fall back to service properties
return value;
}
return attributes.get(key);
}
public Set<Map.Entry<String, Object>> entrySet() {
if (entries != null) {
return entries;
}
Set<Map.Entry<String, Object>> all = new HashSet<Map.Entry<String, Object>>(attributes.size() + properties.size());
all.addAll(attributes.entrySet());
all.addAll(properties.entrySet());
return entries = Collections.unmodifiableSet(all);
}
}
}
/**
* Stores a set of CapabilityPermission permissions.
*
* @see java.security.Permission
* @see java.security.Permissions
* @see java.security.PermissionCollection
*/
final class CapabilityPermissionCollection extends PermissionCollection {
static final long serialVersionUID = -615322242639008920L;
/**
* Table of permissions.
*
* @serial
* @GuardedBy this
*/
private Map<String, CapabilityPermission> permissions;
/**
* Boolean saying if "*" is in the collection.
*
* @serial
* @GuardedBy this
*/
private boolean all_allowed;
/**
* Table of permissions with filter expressions.
*
* @serial
* @GuardedBy this
*/
private Map<String, CapabilityPermission> filterPermissions;
/**
* Creates an empty CapabilityPermissionCollection object.
*/
public CapabilityPermissionCollection() {
permissions = new HashMap<String, CapabilityPermission>();
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
* CapabilityPermission object.
* @throws SecurityException If this {@code CapabilityPermissionCollection}
* object has been marked read-only.
*/
public void add(final Permission permission) {
if (!(permission instanceof CapabilityPermission)) {
throw new IllegalArgumentException("invalid permission: " + permission);
}
if (isReadOnly()) {
throw new SecurityException("attempt to add a Permission to a " + "readonly PermissionCollection");
}
final CapabilityPermission cp = (CapabilityPermission) permission;
if (cp.bundle != null) {
throw new IllegalArgumentException("cannot add to collection: " + cp);
}
final String name = cp.getName();
final Filter f = cp.filter;
synchronized (this) {
/* select the bucket for the permission */
Map<String, CapabilityPermission> pc;
if (f != null) {
pc = filterPermissions;
if (pc == null) {
filterPermissions = pc = new HashMap<String, CapabilityPermission>();
}
} else {
pc = permissions;
}
final CapabilityPermission existing = pc.get(name);
if (existing != null) {
final int oldMask = existing.action_mask;
final int newMask = cp.action_mask;
if (oldMask != newMask) {
pc.put(name, new CapabilityPermission(name, oldMask | newMask));
}
} else {
pc.put(name, cp);
}
if (!all_allowed) {
if (name.equals("*")) {
all_allowed = true;
}
}
}
}
/**
* Determines if a set of permissions implies the permissions expressed in
* {@code permission}.
*
* @param permission The Permission object to compare.
* @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 CapabilityPermission)) {
return false;
}
final CapabilityPermission requested = (CapabilityPermission) permission;
/* if requested permission has a filter, then it is an invalid argument */
if (requested.filter != null) {
return false;
}
String requestedName = requested.getName();
final int desired = requested.action_mask;
int effective = CapabilityPermission.ACTION_NONE;
Collection<CapabilityPermission> perms;
synchronized (this) {
Map<String, CapabilityPermission> pc = permissions;
CapabilityPermission cp;
/* short circuit if the "*" Permission was added */
if (all_allowed) {
cp = pc.get("*");
if (cp != null) {
effective |= cp.action_mask;
if ((effective & desired) == desired) {
return true;
}
}
}
/*
* strategy: Check for full match first. Then work our way up the
* name looking for matches on a.b.*
*/
cp = pc.get(requestedName);
if (cp != null) {
/* we have a direct hit! */
effective |= cp.action_mask;
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) + "*";
cp = pc.get(requestedName);
if (cp != null) {
effective |= cp.action_mask;
if ((effective & desired) == desired) {
return true;
}
}
offset = last - 1;
}
/*
* we don't have to check for "*" as it was already checked before
* we were called.
*/
pc = filterPermissions;
if (pc == null) {
return false;
}
perms = pc.values();
}
/* iterate one by one over filteredPermissions */
for (CapabilityPermission perm : perms) {
if (perm.implies0(requested, effective)) {
return true;
}
}
return false;
}
/**
* Returns an enumeration of all the {@code CapabilityPermission} objects in
* the container.
*
* @return Enumeration of all the CapabilityPermission objects.
*/
public synchronized Enumeration<Permission> elements() {
List<Permission> all = new ArrayList<Permission>(permissions.values());
Map<String, CapabilityPermission> pc = filterPermissions;
if (pc != null) {
all.addAll(pc.values());
}
return Collections.enumeration(all);
}
/* serialization logic */
private static final ObjectStreamField[] serialPersistentFields = {new ObjectStreamField("permissions", HashMap.class), new ObjectStreamField("all_allowed", Boolean.TYPE),
new ObjectStreamField("filterPermissions", HashMap.class) };
private synchronized void writeObject(ObjectOutputStream out) throws IOException {
ObjectOutputStream.PutField pfields = out.putFields();
pfields.put("permissions", permissions);
pfields.put("all_allowed", all_allowed);
pfields.put("filterPermissions", filterPermissions);
out.writeFields();
}
private synchronized void readObject(java.io.ObjectInputStream in) throws IOException, ClassNotFoundException {
ObjectInputStream.GetField gfields = in.readFields();
HashMap<String, CapabilityPermission> p = (HashMap<String, CapabilityPermission>) gfields.get("permissions", null);
permissions = p;
all_allowed = gfields.get("all_allowed", false);
HashMap<String, CapabilityPermission> fp = (HashMap<String, CapabilityPermission>) gfields.get("filterPermissions", null);
filterPermissions = fp;
}
}