| /* |
| * Copyright (c) 1996, 2014, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package sun.rmi.transport; |
| |
| import java.io.IOException; |
| import java.io.ObjectOutput; |
| import java.rmi.MarshalException; |
| import java.rmi.NoSuchObjectException; |
| import java.rmi.Remote; |
| import java.rmi.RemoteException; |
| import java.rmi.server.LogStream; |
| import java.rmi.server.ObjID; |
| import java.rmi.server.RemoteCall; |
| import java.rmi.server.RemoteServer; |
| import java.rmi.server.ServerNotActiveException; |
| import java.security.AccessControlContext; |
| import java.security.AccessController; |
| import java.security.Permissions; |
| import java.security.PrivilegedAction; |
| import java.security.ProtectionDomain; |
| import sun.rmi.runtime.Log; |
| import sun.rmi.server.Dispatcher; |
| import sun.rmi.server.UnicastServerRef; |
| |
| /** |
| * Transport abstraction for enabling communication between different |
| * VMs. |
| * |
| * @author Ann Wollrath |
| */ |
| @SuppressWarnings("deprecation") |
| public abstract class Transport { |
| |
| /** "transport" package log level */ |
| static final int logLevel = LogStream.parseLevel(getLogLevel()); |
| |
| private static String getLogLevel() { |
| return java.security.AccessController.doPrivileged( |
| (PrivilegedAction<String>) () -> System.getProperty("sun.rmi.transport.logLevel")); |
| } |
| |
| /* transport package log */ |
| static final Log transportLog = |
| Log.getLog("sun.rmi.transport.misc", "transport", Transport.logLevel); |
| |
| /** References the current transport when a call is being serviced */ |
| private static final ThreadLocal<Transport> currentTransport = new ThreadLocal<>(); |
| |
| /** ObjID for DGCImpl */ |
| private static final ObjID dgcID = new ObjID(ObjID.DGC_ID); |
| |
| /** AccessControlContext for setting context ClassLoader */ |
| private static final AccessControlContext SETCCL_ACC; |
| static { |
| Permissions perms = new Permissions(); |
| perms.add(new RuntimePermission("setContextClassLoader")); |
| ProtectionDomain[] pd = { new ProtectionDomain(null, perms) }; |
| SETCCL_ACC = new AccessControlContext(pd); |
| } |
| |
| /** |
| * Returns a <I>Channel</I> that generates connections to the |
| * endpoint <I>ep</I>. A Channel is an object that creates and |
| * manages connections of a particular type to some particular |
| * address space. |
| * @param ep the endpoint to which connections will be generated. |
| * @return the channel or null if the transport cannot |
| * generate connections to this endpoint |
| */ |
| public abstract Channel getChannel(Endpoint ep); |
| |
| /** |
| * Removes the <I>Channel</I> that generates connections to the |
| * endpoint <I>ep</I>. |
| */ |
| public abstract void free(Endpoint ep); |
| |
| /** |
| * Export the object so that it can accept incoming calls. |
| */ |
| public void exportObject(Target target) throws RemoteException { |
| target.setExportedTransport(this); |
| ObjectTable.putTarget(target); |
| } |
| |
| /** |
| * Invoked when an object that was exported on this transport has |
| * become unexported, either by being garbage collected or by |
| * being explicitly unexported. |
| **/ |
| protected void targetUnexported() { } |
| |
| /** |
| * Returns the current transport if a call is being serviced, otherwise |
| * returns null. |
| **/ |
| static Transport currentTransport() { |
| return currentTransport.get(); |
| } |
| |
| /** |
| * Verify that the current access control context has permission to accept |
| * the connection being dispatched by the current thread. The current |
| * access control context is passed as a parameter to avoid the overhead of |
| * an additional call to AccessController.getContext. |
| */ |
| protected abstract void checkAcceptPermission(AccessControlContext acc); |
| |
| /** |
| * Sets the context class loader for the current thread. |
| */ |
| private static void setContextClassLoader(ClassLoader ccl) { |
| AccessController.doPrivileged((PrivilegedAction<Void>)() -> { |
| Thread.currentThread().setContextClassLoader(ccl); |
| return null; |
| }, SETCCL_ACC); |
| } |
| |
| /** |
| * Service an incoming remote call. When a message arrives on the |
| * connection indicating the beginning of a remote call, the |
| * threads are required to call the <I>serviceCall</I> method of |
| * their transport. The default implementation of this method |
| * locates and calls the dispatcher object. Ordinarily a |
| * transport implementation will not need to override this method. |
| * At the entry to <I>tr.serviceCall(conn)</I>, the connection's |
| * input stream is positioned at the start of the incoming |
| * message. The <I>serviceCall</I> method processes the incoming |
| * remote invocation and sends the result on the connection's |
| * output stream. If it returns "true", then the remote |
| * invocation was processed without error and the transport can |
| * cache the connection. If it returns "false", a protocol error |
| * occurred during the call, and the transport should destroy the |
| * connection. |
| */ |
| public boolean serviceCall(final RemoteCall call) { |
| try { |
| /* read object id */ |
| final Remote impl; |
| ObjID id; |
| |
| try { |
| id = ObjID.read(call.getInputStream()); |
| } catch (java.io.IOException e) { |
| throw new MarshalException("unable to read objID", e); |
| } |
| |
| /* get the remote object */ |
| Transport transport = id.equals(dgcID) ? null : this; |
| Target target = |
| ObjectTable.getTarget(new ObjectEndpoint(id, transport)); |
| |
| if (target == null || (impl = target.getImpl()) == null) { |
| throw new NoSuchObjectException("no such object in table"); |
| } |
| |
| final Dispatcher disp = target.getDispatcher(); |
| target.incrementCallCount(); |
| try { |
| /* call the dispatcher */ |
| transportLog.log(Log.VERBOSE, "call dispatcher"); |
| |
| final AccessControlContext acc = |
| target.getAccessControlContext(); |
| ClassLoader ccl = target.getContextClassLoader(); |
| |
| ClassLoader savedCcl = Thread.currentThread().getContextClassLoader(); |
| |
| try { |
| setContextClassLoader(ccl); |
| currentTransport.set(this); |
| try { |
| java.security.AccessController.doPrivileged( |
| new java.security.PrivilegedExceptionAction<Void>() { |
| public Void run() throws IOException { |
| checkAcceptPermission(acc); |
| disp.dispatch(impl, call); |
| return null; |
| } |
| }, acc); |
| } catch (java.security.PrivilegedActionException pae) { |
| throw (IOException) pae.getException(); |
| } |
| } finally { |
| setContextClassLoader(savedCcl); |
| currentTransport.set(null); |
| } |
| |
| } catch (IOException ex) { |
| transportLog.log(Log.BRIEF, |
| "exception thrown by dispatcher: ", ex); |
| return false; |
| } finally { |
| target.decrementCallCount(); |
| } |
| |
| } catch (RemoteException e) { |
| |
| // if calls are being logged, write out exception |
| if (UnicastServerRef.callLog.isLoggable(Log.BRIEF)) { |
| // include client host name if possible |
| String clientHost = ""; |
| try { |
| clientHost = "[" + |
| RemoteServer.getClientHost() + "] "; |
| } catch (ServerNotActiveException ex) { |
| } |
| String message = clientHost + "exception: "; |
| UnicastServerRef.callLog.log(Log.BRIEF, message, e); |
| } |
| |
| /* We will get a RemoteException if either a) the objID is |
| * not readable, b) the target is not in the object table, or |
| * c) the object is in the midst of being unexported (note: |
| * NoSuchObjectException is thrown by the incrementCallCount |
| * method if the object is being unexported). Here it is |
| * relatively safe to marshal an exception to the client |
| * since the client will not have seen a return value yet. |
| */ |
| try { |
| ObjectOutput out = call.getResultStream(false); |
| UnicastServerRef.clearStackTraces(e); |
| out.writeObject(e); |
| call.releaseOutputStream(); |
| |
| } catch (IOException ie) { |
| transportLog.log(Log.BRIEF, |
| "exception thrown marshalling exception: ", ie); |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| } |