/**
* $RCSfile$
* $Revision$
* $Date$
*
* Copyright 2003-2007 Jive Software.
*
* 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.jivesoftware.smackx.jingle.nat;
import java.io.IOException;
import java.net.ServerSocket;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smackx.jingle.JingleSession;
import org.jivesoftware.smackx.jingle.SmackLogger;
/**
* A TransportResolver is used for obtaining a list of valid transport
* candidates. A transport candidate is composed by an IP address and a port number.
* It is called candidate, because it can be elected or not.
*
* @author Thiago Camargo
* @author Alvaro Saurin <alvaro.saurin@gmail.com>
*/
public abstract class TransportResolver {
private static final SmackLogger LOGGER = SmackLogger.getLogger(TransportResolver.class);
public enum Type {
rawupd, ice
}
;
public Type getType() {
return type;
}
public void setType(Type type) {
this.type = type;
}
public Type type = Type.rawupd;
// the time, in milliseconds, before a check aborts
public static final int CHECK_TIMEOUT = 3000;
// Listeners for events
private final ArrayList<TransportResolverListener> listeners = new ArrayList<TransportResolverListener>();
// TRue if the resolver is working
private boolean resolving;
// This will be true when all the transport candidates have been gathered...
private boolean resolved;
// This indicates that a transport resolver is initialized
private boolean initialized = false;
// We store a list of candidates internally, just in case there are several
// possibilities. When the user asks for a transport, we return the best
// one.
protected final List<TransportCandidate> candidates = new ArrayList<TransportCandidate>();
/**
* Default constructor.
*/
protected TransportResolver() {
super();
resolving = false;
resolved = false;
}
/**
* Initialize the Resolver
*/
public abstract void initialize() throws XMPPException;
/**
* Start a the resolution.
*/
public abstract void resolve(JingleSession session) throws XMPPException;
/**
* Clear the list of candidates and start a new resolution process.
*
* @throws XMPPException
*/
public void clear() throws XMPPException {
cancel();
candidates.clear();
}
/**
* Cancel any asynchronous resolution operation.
*/
public abstract void cancel() throws XMPPException;
/**
* Return true if the resolver is working.
*
* @return true if the resolver is working.
*/
public boolean isResolving() {
return resolving;
}
/**
* Return true if the resolver has finished the search for transport
* candidates.
*
* @return true if the search has finished
*/
public boolean isResolved() {
return resolved;
}
/**
* Set the Transport Resolver as initialized.
*/
public synchronized void setInitialized() {
initialized = true;
}
/**
* Chack if the Transport Resolver is initialized
*
* @return
*/
public synchronized boolean isInitialized() {
return initialized;
}
/**
* Indicate the beggining of the resolution process. This method must be
* used by subclasses at the begining of their resolve() method.
*/
protected synchronized void setResolveInit() {
resolved = false;
resolving = true;
triggerResolveInit();
}
/**
* Indicate the end of the resolution process. This method must be used by
* subclasses at the begining of their resolve() method.
*/
protected synchronized void setResolveEnd() {
resolved = true;
resolving = false;
triggerResolveEnd();
}
// Listeners management
/**
* Add a transport resolver listener.
*
* @param li The transport resolver listener to be added.
*/
public void addListener(TransportResolverListener li) {
synchronized (listeners) {
listeners.add(li);
}
}
/**
* Removes a transport resolver listener.
*
* @param li The transport resolver listener to be removed
*/
public void removeListener(TransportResolverListener li) {
synchronized (listeners) {
listeners.remove(li);
}
}
/**
* Get the list of listeners
*
* @return the list of listeners
*/
public ArrayList<TransportResolverListener> getListenersList() {
synchronized (listeners) {
return new ArrayList<TransportResolverListener>(listeners);
}
}
/**
* Trigger a new candidate added event.
*
* @param cand The candidate added to the list of candidates.
*/
protected void triggerCandidateAdded(TransportCandidate cand) {
Iterator<TransportResolverListener> iter = getListenersList().iterator();
while (iter.hasNext()) {
TransportResolverListener trl = iter.next();
if (trl instanceof TransportResolverListener.Resolver) {
TransportResolverListener.Resolver li = (TransportResolverListener.Resolver) trl;
LOGGER.debug("triggerCandidateAdded : " + cand.getLocalIp());
li.candidateAdded(cand);
}
}
}
/**
* Trigger a event notifying the initialization of the resolution process.
*/
private void triggerResolveInit() {
Iterator<TransportResolverListener> iter = getListenersList().iterator();
while (iter.hasNext()) {
TransportResolverListener trl = iter.next();
if (trl instanceof TransportResolverListener.Resolver) {
TransportResolverListener.Resolver li = (TransportResolverListener.Resolver) trl;
li.init();
}
}
}
/**
* Trigger a event notifying the obtention of all the candidates.
*/
private void triggerResolveEnd() {
Iterator<TransportResolverListener> iter = getListenersList().iterator();
while (iter.hasNext()) {
TransportResolverListener trl = iter.next();
if (trl instanceof TransportResolverListener.Resolver) {
TransportResolverListener.Resolver li = (TransportResolverListener.Resolver) trl;
li.end();
}
}
}
// Candidates management
/**
* Clear the list of candidate
*/
protected void clearCandidates() {
synchronized (candidates) {
candidates.clear();
}
}
/**
* Add a new transport candidate
*
* @param cand The candidate to add
*/
protected void addCandidate(TransportCandidate cand) {
synchronized (candidates) {
if (!candidates.contains(cand))
candidates.add(cand);
}
// Notify the listeners
triggerCandidateAdded(cand);
}
/**
* Get an iterator for the list of candidates
*
* @return an iterator
*/
public Iterator<TransportCandidate> getCandidates() {
synchronized (candidates) {
return Collections.unmodifiableList(new ArrayList<TransportCandidate>(candidates)).iterator();
}
}
/**
* Get the candididate with the highest preference.
*
* @return The best candidate, according to the preference order.
*/
public TransportCandidate getPreferredCandidate() {
TransportCandidate result = null;
ArrayList<ICECandidate> cands = new ArrayList<ICECandidate>();
for (TransportCandidate tpcan : getCandidatesList()) {
if (tpcan instanceof ICECandidate)
cands.add((ICECandidate) tpcan);
}
// (ArrayList<ICECandidate>) getCandidatesList();
if (cands.size() > 0) {
Collections.sort(cands);
// Return the last candidate
result = (TransportCandidate) cands.get(cands.size() - 1);
LOGGER.debug("Result: " + result.getIp());
}
return result;
}
/**
* Get the numer of transport candidates.
*
* @return The length of the transport candidates list.
*/
public int getCandidateCount() {
synchronized (candidates) {
return candidates.size();
}
}
/**
* Get the list of candidates
*
* @return the list of transport candidates
*/
public List<TransportCandidate> getCandidatesList() {
List<TransportCandidate> result = null;
synchronized (candidates) {
result = new ArrayList<TransportCandidate>(candidates);
}
return result;
}
/**
* Get the n-th candidate
*
* @return a transport candidate
*/
public TransportCandidate getCandidate(int i) {
TransportCandidate cand;
synchronized (candidates) {
cand = (TransportCandidate) candidates.get(i);
}
return cand;
}
/**
* Initialize Transport Resolver and wait until it is complete unitialized.
*/
public void initializeAndWait() throws XMPPException {
this.initialize();
try {
LOGGER.debug("Initializing transport resolver...");
while (!this.isInitialized()) {
LOGGER.debug("Resolver init still pending");
Thread.sleep(1000);
}
LOGGER.debug("Transport resolved\n");
}
catch (Exception e) {
e.printStackTrace();
}
}
/**
* Obtain a free port we can use.
*
* @return A free port number.
*/
protected int getFreePort() {
ServerSocket ss;
int freePort = 0;
for (int i = 0; i < 10; i++) {
freePort = (int) (10000 + Math.round(Math.random() * 10000));
freePort = freePort % 2 == 0 ? freePort : freePort + 1;
try {
ss = new ServerSocket(freePort);
freePort = ss.getLocalPort();
ss.close();
return freePort;
}
catch (IOException e) {
e.printStackTrace();
}
}
try {
ss = new ServerSocket(0);
freePort = ss.getLocalPort();
ss.close();
}
catch (IOException e) {
e.printStackTrace();
}
return freePort;
}
}