| /* |
| * $Header: /cvshome/build/org.osgi.service.event/src/org/osgi/service/event/TopicPermission.java,v 1.11 2006/06/16 16:31:48 hargrave Exp $ |
| * |
| * Copyright (c) OSGi Alliance (2005, 2006). 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.event; |
| |
| import java.io.IOException; |
| import java.security.Permission; |
| import java.security.PermissionCollection; |
| import java.util.Enumeration; |
| import java.util.Hashtable; |
| |
| /** |
| * A bundle's authority to publish or subscribe to event on a topic. |
| * |
| * <p> |
| * A topic is a slash-separated string that defines a topic. |
| * <p> |
| * For example: |
| * |
| * <pre> |
| * org/osgi/service/foo/FooEvent/ACTION |
| * </pre> |
| * |
| * <p> |
| * <code>TopicPermission</code> has two actions: <code>publish</code> and |
| * <code>subscribe</code>. |
| * |
| * @version $Revision: 1.11 $ |
| */ |
| public final class TopicPermission extends Permission { |
| static final long serialVersionUID = -5855563886961618300L; |
| /** |
| * The action string <code>publish</code>. |
| */ |
| public final static String PUBLISH = "publish"; //$NON-NLS-1$ |
| /** |
| * The action string <code>subscribe</code>. |
| */ |
| public final static String SUBSCRIBE = "subscribe"; //$NON-NLS-1$ |
| private final static int ACTION_PUBLISH = 0x00000001; |
| private final static int ACTION_SUBSCRIBE = 0x00000002; |
| private final static int ACTION_ALL = ACTION_PUBLISH |
| | ACTION_SUBSCRIBE; |
| private final static int ACTION_NONE = 0; |
| /** |
| * The actions mask. |
| */ |
| private transient int action_mask = ACTION_NONE; |
| |
| /** |
| * prefix if the name is wildcarded. |
| */ |
| private transient String prefix; |
| |
| /** |
| * The actions in canonical form. |
| * |
| * @serial |
| */ |
| private String actions = null; |
| |
| /** |
| * Defines the authority to publich and/or subscribe to a topic within the |
| * EventAdmin service. |
| * <p> |
| * The name is specified as a slash-separated string. Wildcards may be used. |
| * For example: |
| * |
| * <pre> |
| * org/osgi/service/fooFooEvent/ACTION |
| * com/isv/* |
| * * |
| * </pre> |
| * |
| * <p> |
| * A bundle that needs to publish events on a topic must have the |
| * appropriate <code>TopicPermission</code> for that topic; similarly, a |
| * bundle that needs to subscribe to events on a topic must have the |
| * appropriate <code>TopicPermssion</code> for that topic. |
| * <p> |
| * |
| * @param name Topic name. |
| * @param actions <code>publish</code>,<code>subscribe</code> |
| * (canonical order). |
| */ |
| public TopicPermission(String name, String actions) { |
| this(name, getMask(actions)); |
| } |
| |
| /** |
| * Package private constructor used by TopicPermissionCollection. |
| * |
| * @param name class name |
| * @param mask action mask |
| */ |
| TopicPermission(String name, int mask) { |
| super(name); |
| init(name, mask); |
| } |
| |
| /** |
| * Called by constructors and when deserialized. |
| * |
| * @param name topic name |
| * @param mask action mask |
| */ |
| private void init(String name, int mask) { |
| if ((name == null) || name.length() == 0) { |
| throw new IllegalArgumentException("invalid name"); //$NON-NLS-1$ |
| } |
| |
| if (name.equals("*")) { |
| prefix = ""; |
| } |
| else |
| if (name.endsWith("/*")) { |
| prefix = name.substring(0, name.length() - 1); |
| } |
| else { |
| prefix = null; |
| } |
| |
| if ((mask == ACTION_NONE) || ((mask & ACTION_ALL) != mask)) { |
| throw new IllegalArgumentException("invalid action string"); //$NON-NLS-1$ |
| } |
| action_mask = mask; |
| } |
| |
| /** |
| * Parse action string into action mask. |
| * |
| * @param actions Action string. |
| * @return action mask. |
| */ |
| private static int getMask(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 >= 8 && (a[i - 8] == 's' || a[i - 8] == 'S') |
| && (a[i - 7] == 'u' || a[i - 7] == 'U') |
| && (a[i - 6] == 'b' || a[i - 6] == 'B') |
| && (a[i - 5] == 's' || a[i - 5] == 'S') |
| && (a[i - 4] == 'c' || a[i - 4] == 'C') |
| && (a[i - 3] == 'r' || a[i - 3] == 'R') |
| && (a[i - 2] == 'i' || a[i - 2] == 'I') |
| && (a[i - 1] == 'b' || a[i - 1] == 'B') |
| && (a[i] == 'e' || a[i] == 'E')) { |
| matchlen = 9; |
| mask |= ACTION_SUBSCRIBE; |
| } |
| else |
| if (i >= 6 && (a[i - 6] == 'p' || a[i - 6] == 'P') |
| && (a[i - 5] == 'u' || a[i - 5] == 'U') |
| && (a[i - 4] == 'b' || a[i - 4] == 'B') |
| && (a[i - 3] == 'l' || a[i - 3] == 'L') |
| && (a[i - 2] == 'i' || a[i - 2] == 'I') |
| && (a[i - 1] == 's' || a[i - 1] == 'S') |
| && (a[i] == 'h' || a[i] == 'H')) { |
| matchlen = 7; |
| mask |= ACTION_PUBLISH; |
| } |
| else { |
| // parse error |
| throw new IllegalArgumentException("invalid permission: " //$NON-NLS-1$ |
| + actions); |
| } |
| // make sure we didn't just match the tail of a word |
| // like "ackbarfpublish". 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); //$NON-NLS-1$ |
| } |
| i--; |
| } |
| // point i at the location of the comma minus one (or -1). |
| i -= matchlen; |
| } |
| if (seencomma) { |
| throw new IllegalArgumentException("invalid permission: " + actions); //$NON-NLS-1$ |
| } |
| return mask; |
| } |
| |
| /** |
| * Determines if the specified permission is implied by this object. |
| * |
| * <p> |
| * This method checks that the topic name of the target is implied by the |
| * topic name of this object. The list of <code>TopicPermission</code> |
| * actions must either match or allow for the list of the target object to |
| * imply the target <code>TopicPermission</code> action. |
| * |
| * <pre> |
| * x/y/*,"publish" -> x/y/z,"publish" is true |
| * *,"subscribe" -> x/y,"subscribe" is true |
| * *,"publish" -> x/y,"subscribe" is false |
| * x/y,"publish" -> x/y/z,"publish" is false |
| * </pre> |
| * |
| * @param p The target permission to interrogate. |
| * @return <code>true</code> if the specified <code>TopicPermission</code> |
| * action is implied by this object; <code>false</code> otherwise. |
| */ |
| public boolean implies(Permission p) { |
| if (p instanceof TopicPermission) { |
| TopicPermission target = (TopicPermission) p; |
| if ((action_mask & target.action_mask) == target.action_mask) { |
| if (prefix != null) { |
| return target.getName().startsWith(prefix); |
| } |
| |
| return target.getName().equals(getName()); |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * Returns the canonical string representation of the |
| * <code>TopicPermission</code> actions. |
| * |
| * <p> |
| * Always returns present <code>TopicPermission</code> actions in the |
| * following order: <code>publish</code>,<code>subscribe</code>. |
| * |
| * @return Canonical string representation of the |
| * <code>TopicPermission</code> actions. |
| */ |
| public String getActions() { |
| if (actions == null) { |
| StringBuffer sb = new StringBuffer(); |
| boolean comma = false; |
| if ((action_mask & ACTION_PUBLISH) == ACTION_PUBLISH) { |
| sb.append(PUBLISH); |
| comma = true; |
| } |
| if ((action_mask & ACTION_SUBSCRIBE) == ACTION_SUBSCRIBE) { |
| if (comma) |
| sb.append(','); |
| sb.append(SUBSCRIBE); |
| } |
| actions = sb.toString(); |
| } |
| return actions; |
| } |
| |
| /** |
| * Returns a new <code>PermissionCollection</code> object suitable for |
| * storing <code>TopicPermission</code> objects. |
| * |
| * @return A new <code>PermissionCollection</code> object. |
| */ |
| public PermissionCollection newPermissionCollection() { |
| return new TopicPermissionCollection(); |
| } |
| |
| /** |
| * Determines the equality of two <code>TopicPermission</code> objects. |
| * |
| * This method checks that specified <code>TopicPermission</code> has the same topic name and |
| * actions as this |
| * <code>TopicPermission</code> object. |
| * |
| * @param obj The object to test for equality with this |
| * <code>TopicPermission</code> object. |
| * @return <code>true</code> if <code>obj</code> is a |
| * <code>TopicPermission</code>, and has the same topic name and |
| * actions as this <code>TopicPermission</code> object; |
| * <code>false</code> otherwise. |
| */ |
| public boolean equals(Object obj) { |
| if (obj == this) { |
| return true; |
| } |
| if (!(obj instanceof TopicPermission)) { |
| return false; |
| } |
| TopicPermission p = (TopicPermission) obj; |
| return (action_mask == p.action_mask) && getName().equals(p.getName()); |
| } |
| |
| /** |
| * Returns the hash code value for this object. |
| * |
| * @return A hash code value for this object. |
| */ |
| public int hashCode() { |
| return getName().hashCode() ^ getActions().hashCode(); |
| } |
| |
| /** |
| * Returns the current action mask. |
| * <p> |
| * Used by the TopicPermissionCollection class. |
| * |
| * @return Current action mask. |
| */ |
| int getMask() { |
| return action_mask; |
| } |
| |
| /** |
| * 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 { |
| // 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(); |
| init(getName(), getMask(actions)); |
| } |
| } |
| |
| /** |
| * Stores a set of <code>TopicPermission</code> permissions. |
| * |
| * @see java.security.Permission |
| * @see java.security.Permissions |
| * @see java.security.PermissionCollection |
| */ |
| final class TopicPermissionCollection extends PermissionCollection { |
| static final long serialVersionUID = -614647783533924048L; |
| /** |
| * Table of permissions. |
| * |
| * @serial |
| */ |
| private Hashtable permissions; |
| /** |
| * Boolean saying if "*" is in the collection. |
| * |
| * @serial |
| */ |
| private boolean all_allowed; |
| |
| /** |
| * Create an empty TopicPermissions object. |
| * |
| */ |
| public TopicPermissionCollection() { |
| permissions = new Hashtable(); |
| all_allowed = false; |
| } |
| |
| /** |
| * Adds a permission to the <code>TopicPermission</code> objects. The key |
| * for the hash is the name. |
| * |
| * @param permission The <code>TopicPermission</code> object to add. |
| * |
| * @throws IllegalArgumentException If the permission is not a |
| * <code>TopicPermission</code> instance. |
| * |
| * @throws SecurityException If this |
| * <code>TopicPermissionCollection</code> object has been |
| * marked read-only. |
| */ |
| public void add(Permission permission) { |
| if (!(permission instanceof TopicPermission)) |
| throw new IllegalArgumentException("invalid permission: " //$NON-NLS-1$ |
| + permission); |
| if (isReadOnly()) |
| throw new SecurityException("attempt to add a Permission to a " //$NON-NLS-1$ |
| + "readonly PermissionCollection"); //$NON-NLS-1$ |
| TopicPermission pp = (TopicPermission) permission; |
| String name = pp.getName(); |
| TopicPermission existing = (TopicPermission) permissions.get(name); |
| if (existing != null) { |
| int oldMask = existing.getMask(); |
| int newMask = pp.getMask(); |
| if (oldMask != newMask) { |
| permissions.put(name, new TopicPermission(name, oldMask |
| | newMask)); |
| } |
| } |
| else { |
| permissions.put(name, permission); |
| } |
| if (!all_allowed) { |
| if (name.equals("*")) //$NON-NLS-1$ |
| all_allowed = true; |
| } |
| } |
| |
| /** |
| * Determines if the specified permissions implies the permissions expressed |
| * in <code>permission</code>. |
| * |
| * @param permission The Permission object to compare with this |
| * <code>TopicPermission</code> object. |
| * |
| * @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(Permission permission) { |
| if (!(permission instanceof TopicPermission)) |
| return false; |
| TopicPermission pp = (TopicPermission) permission; |
| TopicPermission x; |
| int desired = pp.getMask(); |
| int effective = 0; |
| // short circuit if the "*" Permission was added |
| if (all_allowed) { |
| x = (TopicPermission) permissions.get("*"); //$NON-NLS-1$ |
| if (x != null) { |
| effective |= x.getMask(); |
| 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/* |
| String name = pp.getName(); |
| x = (TopicPermission) permissions.get(name); |
| if (x != null) { |
| // we have a direct hit! |
| effective |= x.getMask(); |
| if ((effective & desired) == desired) |
| return true; |
| } |
| // work our way up the tree... |
| int last, offset; |
| offset = name.length() - 1; |
| while ((last = name.lastIndexOf("/", offset)) != -1) { //$NON-NLS-1$ |
| name = name.substring(0, last + 1) + "*"; //$NON-NLS-1$ |
| x = (TopicPermission) permissions.get(name); |
| if (x != null) { |
| effective |= x.getMask(); |
| 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>TopicPermission</code> objects in |
| * the container. |
| * |
| * @return Enumeration of all <code>TopicPermission</code> objects. |
| */ |
| public Enumeration elements() { |
| return permissions.elements(); |
| } |
| } |