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/*
 * 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.ArrayList;
import java.util.Collection;
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 import or export a package.
 * 
 * 

* A package is a dot-separated string that defines a fully qualified Java * package. *

* For example: * *

 * org.osgi.service.http
 * 
* *

* {@code PackagePermission} has three actions: {@code exportonly}, * {@code import} and {@code export}. The {@code export} action, which is * deprecated, implies the {@code import} action. * * @ThreadSafe * @version $Id: e993fbc36b6bff84182a8594af5af3cad8c4e2a3 $ */ public final class PackagePermission extends BasicPermission { static final long serialVersionUID = -5107705877071099135L; /** * The action string {@code export}. The {@code export} action implies the * {@code import} action. * * @deprecated Since 1.5. Use {@code exportonly} instead. */ public final static String EXPORT = "export"; /** * The action string {@code exportonly}. The {@code exportonly} action does * not imply the {@code import} action. * * @since 1.5 */ public final static String EXPORTONLY = "exportonly"; /** * The action string {@code import}. */ public final static String IMPORT = "import"; private final static int ACTION_EXPORT = 0x00000001; private final static int ACTION_IMPORT = 0x00000002; private final static int ACTION_ALL = ACTION_EXPORT | ACTION_IMPORT; 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 PackagePermission. */ transient final Bundle bundle; /** * If this PackagePermission 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 properties; /** * Creates a new {@code PackagePermission} object. * *

* The name is specified as a normal Java package name: a dot-separated * string. Wildcards may be used. * *

	 * name ::= <package name> | <package name ending in ".*"> | *
	 * 
* * Examples: * *
	 * org.osgi.service.http
	 * javax.servlet.*
	 * *
	 * 
* * For the {@code import} action, the name can also be a filter expression. * The filter gives access to the following attributes: *
    *
  • 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.
  • *
  • location - The location of the exporting bundle.
  • *
  • id - The bundle ID of the exporting bundle.
  • *
  • name - The symbolic name of the exporting bundle.
  • *
  • package.name - The name of the requested package.
  • *
* Filter attribute names are processed in a case sensitive manner. * *

* Package Permissions are granted over all possible versions of a package. * * A bundle that needs to export a package must have the appropriate * {@code PackagePermission} for that package; similarly, a bundle that * needs to import a package must have the appropriate * {@code PackagePermssion} for that package. *

* Permission is granted for both classes and resources. * * @param name Package name or filter expression. A filter expression can * only be specified if the specified action is {@code import}. * @param actions {@code exportonly},{@code import} (canonical order). * @throws IllegalArgumentException If the specified name is a filter * expression and either the specified action is not {@code import} * or the filter has an invalid syntax. */ public PackagePermission(String name, String actions) { this(name, parseActions(actions)); if ((filter != null) && ((action_mask & ACTION_ALL) != ACTION_IMPORT)) { throw new IllegalArgumentException("invalid action string for filter expression"); } } /** * Creates a new requested {@code PackagePermission} object to be used by * code that must perform {@code checkPermission} for the {@code import} * action. {@code PackagePermission} objects created with this constructor * cannot be added to a {@code PackagePermission} permission collection. * * @param name The name of the requested package to import. * @param exportingBundle The bundle exporting the requested package. * @param actions The action {@code import}. * @throws IllegalArgumentException If the specified action is not * {@code import} or the name is a filter expression. * @since 1.5 */ public PackagePermission(String name, Bundle exportingBundle, String actions) { super(name); setTransients(name, parseActions(actions)); this.bundle = exportingBundle; if (exportingBundle == null) { throw new IllegalArgumentException("bundle must not be null"); } if (filter != null) { throw new IllegalArgumentException("invalid name"); } if ((action_mask & ACTION_ALL) != ACTION_IMPORT) { throw new IllegalArgumentException("invalid action string"); } } /** * Package private constructor used by PackagePermissionCollection. * * @param name package name * @param mask action mask */ PackagePermission(String name, int mask) { super(name); setTransients(name, mask); 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 >= 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; } 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_IMPORT; } else { if (i >= 9 && (a[i - 9] == 'e' || a[i - 9] == 'E') && (a[i - 8] == 'x' || a[i - 8] == 'X') && (a[i - 7] == 'p' || a[i - 7] == 'P') && (a[i - 6] == 'o' || a[i - 6] == 'O') && (a[i - 5] == 'r' || a[i - 5] == 'R') && (a[i - 4] == 't' || a[i - 4] == 'T') && (a[i - 3] == 'o' || a[i - 3] == 'O') && (a[i - 2] == 'n' || a[i - 2] == 'N') && (a[i - 1] == 'l' || a[i - 1] == 'L') && (a[i] == 'y' || a[i] == 'Y')) { matchlen = 10; mask |= ACTION_EXPORT; } else { // parse error throw new IllegalArgumentException("invalid permission: " + actions); } } // make sure we didn't just match the tail of a word // like "ackbarfimport". 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 the specified permission is implied by this object. * *

* This method checks that the package name of the target is implied by the * package name of this object. The list of {@code PackagePermission} * actions must either match or allow for the list of the target object to * imply the target {@code PackagePermission} action. *

* The permission to export a package implies the permission to import the * named package. * *

	 * x.y.*,"export" -> x.y.z,"export" is true
	 * *,"import" -> x.y, "import"      is true
	 * *,"export" -> x.y, "import"      is true
	 * x.y,"export" -> x.y.z, "export"  is false
	 * 
* * @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 PackagePermission)) { return false; } PackagePermission requested = (PackagePermission) 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 PackagePermission which has already be * validated as a proper argument. The requested PackagePermission * 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(PackagePermission 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 * {@code PackagePermission} actions. * *

* Always returns present {@code PackagePermission} actions in the following * order: {@code EXPORTONLY},{@code IMPORT}. * * @return Canonical string representation of the {@code PackagePermission} * actions. */ public String getActions() { String result = actions; if (result == null) { StringBuffer sb = new StringBuffer(); boolean comma = false; int mask = action_mask; if ((mask & ACTION_EXPORT) == ACTION_EXPORT) { sb.append(EXPORTONLY); comma = true; } if ((mask & ACTION_IMPORT) == ACTION_IMPORT) { if (comma) sb.append(','); sb.append(IMPORT); } actions = result = sb.toString(); } return result; } /** * Returns a new {@code PermissionCollection} object suitable for storing * {@code PackagePermission} objects. * * @return A new {@code PermissionCollection} object. */ public PermissionCollection newPermissionCollection() { return new PackagePermissionCollection(); } /** * Determines the equality of two {@code PackagePermission} objects. * * This method checks that specified package has the same package name and * {@code PackagePermission} actions as this {@code PackagePermission} * object. * * @param obj The object to test for equality with this * {@code PackagePermission} object. * @return {@code true} if {@code obj} is a {@code PackagePermission}, and * has the same package name and actions as this * {@code PackagePermission} object; {@code false} otherwise. */ public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof PackagePermission)) { return false; } PackagePermission pp = (PackagePermission) obj; return (action_mask == pp.action_mask) && getName().equals(pp.getName()) && ((bundle == pp.bundle) || ((bundle != null) && bundle.equals(pp.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(getName(), parseActions(actions)); } /** * Called by {@code <@link PackagePermission#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 getProperties() { Map result = properties; if (result != null) { return result; } final Map map = new HashMap(5); map.put("package.name", getName()); if (bundle != null) { AccessController.doPrivileged(new PrivilegedAction() { 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 PackagePermission} permissions. * * @see java.security.Permission * @see java.security.Permissions * @see java.security.PermissionCollection */ final class PackagePermissionCollection extends PermissionCollection { static final long serialVersionUID = -3350758995234427603L; /** * Table of permissions with names. * * @GuardedBy this */ private transient Map 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 filterPermissions; /** * Create an empty PackagePermissions object. */ public PackagePermissionCollection() { permissions = new HashMap(); all_allowed = false; } /** * Adds a permission to this permission collection. * * @param permission The {@code PackagePermission} object to add. * @throws IllegalArgumentException If the specified permission is not a * {@code PackagePermission} instance or was constructed with a * Bundle object. * @throws SecurityException If this {@code PackagePermissionCollection} * object has been marked read-only. */ public void add(final Permission permission) { if (!(permission instanceof PackagePermission)) { throw new IllegalArgumentException("invalid permission: " + permission); } if (isReadOnly()) { throw new SecurityException("attempt to add a Permission to a " + "readonly PermissionCollection"); } final PackagePermission pp = (PackagePermission) permission; if (pp.bundle != null) { throw new IllegalArgumentException("cannot add to collection: " + pp); } final String name = pp.getName(); final Filter f = pp.filter; synchronized (this) { /* select the bucket for the permission */ Map pc; if (f != null) { pc = filterPermissions; if (pc == null) { filterPermissions = pc = new HashMap(); } } else { pc = permissions; } final PackagePermission existing = pc.get(name); if (existing != null) { final int oldMask = existing.action_mask; final int newMask = pp.action_mask; if (oldMask != newMask) { pc.put(name, new PackagePermission(name, oldMask | newMask)); } } else { pc.put(name, pp); } 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 PackagePermission} 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 PackagePermission)) { return false; } final PackagePermission requested = (PackagePermission) 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 = PackagePermission.ACTION_NONE; Collection perms; synchronized (this) { Map pc = permissions; PackagePermission pp; /* short circuit if the "*" Permission was added */ if (all_allowed) { pp = pc.get("*"); if (pp != null) { effective |= pp.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.* */ pp = pc.get(requestedName); if (pp != null) { /* we have a direct hit! */ effective |= pp.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) + "*"; pp = pc.get(requestedName); if (pp != null) { effective |= pp.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 (PackagePermission perm : perms) { if (perm.implies0(requested, effective)) { return true; } } return false; } /** * Returns an enumeration of all {@code PackagePermission} objects in the * container. * * @return Enumeration of all {@code PackagePermission} objects. */ public synchronized Enumeration elements() { List all = new ArrayList(permissions.values()); Map pc = filterPermissions; if (pc != null) { all.addAll(pc.values()); } return Collections.enumeration(all); } /* serialization logic */ private static final ObjectStreamField[] serialPersistentFields = {new ObjectStreamField("permissions", Hashtable.class), new ObjectStreamField("all_allowed", Boolean.TYPE), new ObjectStreamField("filterPermissions", HashMap.class) }; private synchronized void writeObject(ObjectOutputStream out) throws IOException { Hashtable hashtable = new Hashtable(permissions); ObjectOutputStream.PutField pfields = out.putFields(); pfields.put("permissions", hashtable); 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(); Hashtable hashtable = (Hashtable) gfields.get("permissions", null); permissions = new HashMap(hashtable); all_allowed = gfields.get("all_allowed", false); HashMap fp = (HashMap) gfields.get("filterPermissions", null); filterPermissions = fp; } }