From 56e4e96278a4421de5c4d1bd43ff0cf96f9fad03 Mon Sep 17 00:00:00 2001 From: rfeng Date: Tue, 1 Dec 2009 21:59:20 +0000 Subject: Update to the latest OSGi remoteserviceadmin apis git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@885958 13f79535-47bb-0310-9956-ffa450edef68 --- .../remoteserviceadmin/EndpointPermission.java | 943 +++++++++++++++++++++ 1 file changed, 943 insertions(+) create mode 100644 sca-java-2.x/trunk/modules/node-impl-osgi/src/main/java/org/osgi/service/remoteserviceadmin/EndpointPermission.java (limited to 'sca-java-2.x/trunk/modules/node-impl-osgi/src/main/java/org/osgi/service/remoteserviceadmin/EndpointPermission.java') diff --git a/sca-java-2.x/trunk/modules/node-impl-osgi/src/main/java/org/osgi/service/remoteserviceadmin/EndpointPermission.java b/sca-java-2.x/trunk/modules/node-impl-osgi/src/main/java/org/osgi/service/remoteserviceadmin/EndpointPermission.java new file mode 100644 index 0000000000..0bfdcd334b --- /dev/null +++ b/sca-java-2.x/trunk/modules/node-impl-osgi/src/main/java/org/osgi/service/remoteserviceadmin/EndpointPermission.java @@ -0,0 +1,943 @@ +/* + * Copyright (c) OSGi Alliance (2000, 2009). 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.remoteserviceadmin; + +// TODO Hacked from ServiePermission + +import java.io.IOException; +import java.io.NotSerializableException; +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.Collection; +import java.util.Collections; +import java.util.Dictionary; +import java.util.Enumeration; +import java.util.HashMap; +import java.util.Hashtable; +import java.util.Iterator; +import java.util.List; +import java.util.Map; + +import org.osgi.framework.Constants; +import org.osgi.framework.Filter; +import org.osgi.framework.FrameworkUtil; +import org.osgi.framework.InvalidSyntaxException; + +/** + * 
+ * -------------------------------------------------------------
+ * THIS CLASS IS A PLACEHOLDER (COPIED FROM SERVICE PERMISSION)!
+ * -------------------------------------------------------------
+ *
+ * + * A bundle's authority to register or get a service. + * + * Permission to get a service is required in order to detect events regarding + * the service. Untrusted bundles should not be able to detect the presence of + * certain services unless they have the appropriate + * EndpointPermission to get the specific service. + * + * @ThreadSafe + * @version $Revision$ + */ + +public final class EndpointPermission extends BasicPermission { + static final long serialVersionUID = -7662148639076511574L; + /** + * The action string export. + */ + public final static String EXPORT = "export"; + /** + * The action string import. + */ + public final static String IMPORT = "import"; + /** + * The action string read. + */ + public final static String READ = "read"; + + private final static int ACTION_EXPORT = 0x00000001; + private final static int ACTION_IMPORT = 0x00000002; + private final static int ACTION_READ = 0x00000004; + private final static int ACTION_ALL = ACTION_EXPORT + | ACTION_IMPORT + | ACTION_READ; + 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 service used by this EndpointPermission. Must be null if not + * constructed with a service. + */ + transient final EndpointDescription endpoint; + + /** + * The object classes for this EndpointPermission. Must be null if not + * constructed with a service. + */ + transient final String[] objectClass; + + /** + * If this EndpointPermission was constructed with a filter, this holds a + * Filter matching object used to evaluate the filter in implies. + */ + transient Filter filter; + + /** + * This dictionary 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 Dictionary properties; + + /** + * True if constructed with a name and the name is "*" or ends with ".*". + */ + private transient boolean wildcard; + + /** + * If constructed with a name and the name ends with ".*", this contains the + * name without the final "*". + */ + private transient String prefix; + + /** + * Create a new EndpointPermission. + * + *

+ * The name of the service is specified as a fully qualified class name. + * Wildcards may be used. + * + * 

+	 * name ::= <class name> | <class name ending in ".*"> | *
+	 *
+ * + * Examples: + * + * 
+	 * org.osgi.service.http.HttpService
+	 * org.osgi.service.http.*
+	 * *
+	 *
+ * + * For the get action, the name can also be a filter + * expression. The filter gives access to the service properties as well as + * the following attributes: + * + * Since the above attribute names may conflict with service property names + * used by a service, you can prefix an attribute name with '@' in the + * filter expression to match against the service property and not one of + * the above attributes. Filter attribute names are processed in a case + * sensitive manner unless the attribute references a service property. + * Service properties names are case insensitive. + * + *

+ * There are two possible actions: get and + * register. The get permission allows the owner + * of this permission to obtain a service with this name. The + * register permission allows the bundle to register a service + * under that name. + * + * @param name The service class name + * @param actions get,register (canonical order) + * @throws IllegalArgumentException If the specified name is a filter + * expression and either the specified action is not + * get or the filter has an invalid syntax. + */ + public EndpointPermission(String name, String actions) { + this(name, parseActions(actions)); + if ((filter != null) && ((action_mask & ACTION_ALL) != ACTION_EXPORT)) { + throw new IllegalArgumentException( + "invalid action string for filter expression"); + } + } + + /** + * Creates a new requested EndpointPermission object to be used + * by code that must perform checkPermission for the + * get action. EndpointPermission objects created + * with this constructor cannot be added to a + * EndpointPermission permission collection. + * + * @param endpoint The requested service. + * @param actions The action get. + * @throws IllegalArgumentException If the specified action is not + * get or reference is null. + * @since 1.5 + */ + public EndpointPermission(EndpointDescription endpoint, String actions) { + super(createName(endpoint)); + setTransients(null, parseActions(actions)); + this.endpoint = endpoint; + this.objectClass = (String[]) endpoint.getProperties().get( + Constants.OBJECTCLASS); + if ((action_mask & ACTION_ALL) != ACTION_EXPORT) { + throw new IllegalArgumentException("invalid action string"); + } + } + + /** + * Create a permission name from a EndpointDescription TODO Needs work + * + * @param endpoint EndpointDescription to use to create permission name. + * @return permission name. + */ + private static String createName(EndpointDescription endpoint) { + if (endpoint == null) { + throw new IllegalArgumentException("reference must not be null"); + } + StringBuffer sb = new StringBuffer("(service.id="); + // TODO sb.append(endpoint.getProperty(Constants.SERVICE_ID)); + sb.append(")"); + return sb.toString(); + } + + /** + * Package private constructor used by EndpointPermissionCollection. + * + * @param name class name + * @param mask action mask + */ + EndpointPermission(String name, int mask) { + super(name); + setTransients(parseFilter(name), mask); + this.endpoint = null; + this.objectClass = null; + } + + /** + * Called by constructors and when deserialized. + * + * @param mask action mask + */ + private void setTransients(Filter f, int mask) { + if ((mask == ACTION_NONE) || ((mask & ACTION_ALL) != mask)) { + throw new IllegalArgumentException("invalid action string"); + } + action_mask = mask; + filter = f; + if (f == null) { + String name = getName(); + int l = name.length(); + /* if "*" or endsWith ".*" */ + wildcard = ((name.charAt(l - 1) == '*') && ((l == 1) || (name + .charAt(l - 2) == '.'))); + if (wildcard && (l > 1)) { + prefix = name.substring(0, l - 1); + } + } + } + + /** + * 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 >= 2 && (a[i - 2] == 'g' || a[i - 2] == 'G') + && (a[i - 1] == 'e' || a[i - 1] == 'E') + && (a[i] == 't' || a[i] == 'T')) { + matchlen = 3; + mask |= ACTION_EXPORT; + + } + else + if (i >= 7 && (a[i - 7] == 'r' || a[i - 7] == 'R') + && (a[i - 6] == 'e' || a[i - 6] == 'E') + && (a[i - 5] == 'g' || a[i - 5] == 'G') + && (a[i - 4] == 'i' || a[i - 4] == 'I') + && (a[i - 3] == 's' || a[i - 3] == 'S') + && (a[i - 2] == 't' || a[i - 2] == 'T') + && (a[i - 1] == 'e' || a[i - 1] == 'E') + && (a[i] == 'r' || a[i] == 'R')) { + matchlen = 8; + mask |= ACTION_IMPORT; + + } + else { + // parse error + throw new IllegalArgumentException("invalid permission: " + + actions); + } + + // make sure we didn't just match the tail of a word + // like "ackbarfregister". 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 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 EndpointPermission object "implies" the + * specified permission. + * + * @param p The target permission to check. + * @return true if the specified permission is implied by this + * object; false otherwise. + */ + public boolean implies(Permission p) { + if (!(p instanceof EndpointPermission)) { + return false; + } + EndpointPermission requested = (EndpointPermission) p; + if (endpoint != 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 EndpointPermission which has already be + * validated as a proper argument. The requested EndpointPermission + * must not have a filter expression. + * @param effective The effective actions with which to start. + * @return true if the specified permission is implied by this + * object; false otherwise. + */ + boolean implies0(EndpointPermission requested, int effective) { + /* check actions first - much faster */ + effective |= action_mask; + final int desired = requested.action_mask; + if ((effective & desired) != desired) { + return false; + } + /* we have name of "*" */ + if (wildcard && (prefix == null)) { + return true; + } + /* if we have a filter */ + Filter f = filter; + if (f != null) { + return f.matchCase(requested.getProperties()); + } + /* if requested permission not created with EndpointDescription */ + String[] requestedNames = requested.objectClass; + if (requestedNames == null) { + return super.implies(requested); + } + /* requested permission created with EndpointDescription */ + if (wildcard) { + int pl = prefix.length(); + for (int i = 0, l = requestedNames.length; i < l; i++) { + String requestedName = requestedNames[i]; + if ((requestedName.length() > pl) + && requestedName.startsWith(prefix)) { + return true; + } + } + } + else { + String name = getName(); + for (int i = 0, l = requestedNames.length; i < l; i++) { + if (requestedNames[i].equals(name)) { + return true; + } + } + } + return false; + } + + /** + * Returns the canonical string representation of the actions. Always + * returns present actions in the following order: get, + * register. + * + * @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_EXPORT) == ACTION_EXPORT) { + sb.append(EXPORT); + comma = true; + } + + if ((mask & ACTION_IMPORT) == ACTION_IMPORT) { + if (comma) + sb.append(','); + sb.append(IMPORT); + } + + actions = result = sb.toString(); + } + + return result; + } + + /** + * Returns a new PermissionCollection object for storing + * EndpointPermission objects. + * + * @return A new PermissionCollection object suitable for + * storing EndpointPermission objects. + */ + public PermissionCollection newPermissionCollection() { + return new EndpointPermissionCollection(); + } + + /** + * Determines the equality of two EndpointPermission objects. + * + * Checks that specified object has the same class name and action as this + * EndpointPermission. + * + * @param obj The object to test for equality. + * @return true if obj is a EndpointPermission, and has the + * same class name and actions as this + * EndpointPermission object; false + * otherwise. + */ + public boolean equals(Object obj) { + if (obj == this) { + return true; + } + + if (!(obj instanceof EndpointPermission)) { + return false; + } + + EndpointPermission sp = (EndpointPermission) obj; + + return (action_mask == sp.action_mask) + && getName().equals(sp.getName()) + && ((endpoint == sp.endpoint) || ((endpoint != null) + && (sp.endpoint != null) && endpoint + .equals(sp.endpoint))); + } + + /** + * 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 (endpoint != null) { + h = 31 * h + endpoint.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 (endpoint != 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(parseFilter(getName()), parseActions(actions)); + } + + /** + * Called by <@link EndpointPermission#implies(Permission)>. + * + * @return a dictionary of properties for this permission. + */ + private Dictionary/* */getProperties() { + Dictionary/* */result = properties; + if (result != null) { + return result; + } + if (endpoint == null) { + result = new Hashtable/* */(1); + if (filter == null) { + result.put(Constants.OBJECTCLASS, new String[] {getName()}); + } + return properties = result; + } + final Map props = new HashMap(4); + // TODO needs work + /* + * final Bundle bundle = endpoint.getBundle(); if (bundle != null) { + * AccessController.doPrivileged(new PrivilegedAction() { 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, endpoint); + } + + private static class Properties extends Dictionary { + private final Map properties; + private final EndpointDescription service; + + Properties(Map properties, EndpointDescription service) { + this.properties = properties; + this.service = service; + } + + public Object get(Object k) { + if (!(k instanceof String)) { + return null; + } + String key = (String) k; + if (key.charAt(0) == '@') { + return service.getProperties().get(key.substring(1)); + } + Object value = properties.get(key); + if (value != null) { // fall back to service properties + return value; + } + return service.getProperties().get(key); + } + + public int size() { + return properties.size() + service.getProperties().size(); + } + + public boolean isEmpty() { + // we can return false because this must never be empty + return false; + } + + public Enumeration keys() { + Collection pk = properties.keySet(); + String spk[] = (String[]) service.getProperties().keySet().toArray( + new String[service.getProperties().size()]); + List all = new ArrayList(pk.size() + spk.length); + all.addAll(pk); + add: for (int i = 0, length = spk.length; i < length; i++) { + String key = spk[i]; + for (Iterator iter = pk.iterator(); iter.hasNext();) { + if (key.equalsIgnoreCase((String) iter.next())) { + continue add; + } + } + all.add(key); + } + return Collections.enumeration(all); + } + + public Enumeration elements() { + Collection pk = properties.keySet(); + String spk[] = (String[]) service.getProperties().keySet().toArray( + new String[service.getProperties().size()]); + List all = new ArrayList(pk.size() + spk.length); + all.addAll(properties.values()); + add: for (int i = 0, length = spk.length; i < length; i++) { + String key = spk[i]; + for (Iterator iter = pk.iterator(); iter.hasNext();) { + if (key.equalsIgnoreCase((String) iter.next())) { + continue add; + } + } + all.add(service.getProperties().get(key)); + } + return Collections.enumeration(all); + } + + public Object put(Object key, Object value) { + throw new UnsupportedOperationException(); + } + + public Object remove(Object key) { + throw new UnsupportedOperationException(); + } + } +} + +/** + * Stores a set of EndpointPermission permissions. + * + * @see java.security.Permission + * @see java.security.Permissions + * @see java.security.PermissionCollection + */ +final class EndpointPermissionCollection extends PermissionCollection { + static final long serialVersionUID = 662615640374640621L; + /** + * Table of permissions. + * + * @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; + + /** + * Creates an empty EndpointPermissions object. + */ + public EndpointPermissionCollection() { + permissions = new HashMap(); + 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 + * EndpointPermission object. + * @throws SecurityException If this + * EndpointPermissionCollection object has been marked + * read-only. + */ + public void add(final Permission permission) { + if (!(permission instanceof EndpointPermission)) { + throw new IllegalArgumentException("invalid permission: " + + permission); + } + if (isReadOnly()) { + throw new SecurityException("attempt to add a Permission to a " + + "readonly PermissionCollection"); + } + + final EndpointPermission sp = (EndpointPermission) permission; + if (sp.endpoint != null) { + throw new IllegalArgumentException("cannot add to collection: " + + sp); + } + + final String name = sp.getName(); + final Filter f = sp.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 EndpointPermission existing = (EndpointPermission) pc + .get(name); + + if (existing != null) { + final int oldMask = existing.action_mask; + final int newMask = sp.action_mask; + if (oldMask != newMask) { + pc.put(name, + new EndpointPermission(name, oldMask | newMask)); + } + } + else { + pc.put(name, sp); + } + + if (!all_allowed) { + if (name.equals("*")) { + all_allowed = true; + } + } + } + } + + /** + * Determines if a set of permissions implies the permissions expressed in + * permission. + * + * @param permission The Permission object to compare. + * @return true if permission is a proper subset + * of a permission in the set; false otherwise. + */ + public boolean implies(final Permission permission) { + if (!(permission instanceof EndpointPermission)) { + return false; + } + final EndpointPermission requested = (EndpointPermission) permission; + /* if requested permission has a filter, then it is an invalid argument */ + if (requested.filter != null) { + return false; + } + + int effective = EndpointPermission.ACTION_NONE; + Collection perms; + synchronized (this) { + final int desired = requested.action_mask; + /* short circuit if the "*" Permission was added */ + if (all_allowed) { + EndpointPermission sp = (EndpointPermission) permissions + .get("*"); + if (sp != null) { + effective |= sp.action_mask; + if ((effective & desired) == desired) { + return true; + } + } + } + + String[] requestedNames = requested.objectClass; + /* if requested permission not created with EndpointDescription */ + if (requestedNames == null) { + effective |= effective(requested.getName(), desired, effective); + if ((effective & desired) == desired) { + return true; + } + } + /* requested permission created with EndpointDescription */ + else { + for (int i = 0, l = requestedNames.length; i < l; i++) { + if ((effective(requestedNames[i], desired, effective) & desired) == desired) { + return true; + } + } + } + Map pc = filterPermissions; + if (pc == null) { + return false; + } + perms = pc.values(); + } + + /* iterate one by one over filteredPermissions */ + for (Iterator iter = perms.iterator(); iter.hasNext();) { + if (((EndpointPermission) iter.next()).implies0(requested, + effective)) { + return true; + } + } + return false; + } + + /** + * Consult permissions map to compute the effective permission for the + * requested permission name. + * + * @param requestedName The requested service name. + * @param desired The desired actions. + * @param effective The effective actions. + * @return The new effective actions. + */ + private int effective(String requestedName, final int desired, int effective) { + final Map pc = permissions; + EndpointPermission sp = (EndpointPermission) pc.get(requestedName); + // strategy: + // Check for full match first. Then work our way up the + // name looking for matches on a.b.* + if (sp != null) { + // we have a direct hit! + effective |= sp.action_mask; + if ((effective & desired) == desired) { + return effective; + } + } + // 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) + "*"; + sp = (EndpointPermission) pc.get(requestedName); + if (sp != null) { + effective |= sp.action_mask; + if ((effective & desired) == desired) { + return effective; + } + } + offset = last - 1; + } + /* + * we don't have to check for "*" as it was already checked before we + * were called. + */ + return effective; + } + + /** + * Returns an enumeration of all the EndpointPermission objects + * in the container. + * + * @return Enumeration of all the EndpointPermission 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); + filterPermissions = (HashMap) gfields.get("filterPermissions", null); + } +} -- cgit v1.2.3