/**
* Creates a listening point from the following address and attempts to
* discover how it is mapped so that using inside the application is possible.
* @param address the [address]:[port] pair where ther request should be
* sent from.
* @return a StunAddress object containing the mapped address or null if
* discovery failed.
* @throws StunException if something fails along the way.
*/
public virtual StunAddress GetMappingFor(StunAddress address)
{
NetAccessPointDescriptor apDesc = new NetAccessPointDescriptor(address);
stunStack.InstallNetAccessPoint(apDesc);
requestSender = new BlockingRequestSender(stunProvider, apDesc);
StunMessageEvent evt = null;
try
{
evt = requestSender.SendRequestAndWaitForResponse(
MessageFactory.CreateBindingRequest(), serverAddress);
}
finally
{
//free the port to allow the application to use it.
stunStack.RemoveNetAccessPoint(apDesc);
}
if (evt != null)
{
Response res = (Response)evt.GetMessage();
MappedAddressAttribute maAtt =
(MappedAddressAttribute)
res.GetAttribute(Attribute.MAPPED_ADDRESS);
if (maAtt != null)
{
StunAddress sa = maAtt.GetAddress();
return(sa);
}
}
return(null);
}
/**
* Called to notify this provider for an incoming message.
* @param event the event object that contains the new message.
*/
public virtual void HandleMessageEvent(StunMessageEvent @event)
{
Message msg = @event.GetMessage();
//request
if (msg is Request)
{
TransactionID serverTid = TransactionID.
CreateTransactionID(msg.GetTransactionID());
serverTransactions.Add(serverTid);
if (requestListener != null)
{
requestListener.requestReceived(@event);
}
}
//response
else if (msg is Response)
{
TransactionID tid = TransactionID.
CreateTransactionID(msg.GetTransactionID());
StunClientTransaction tran = (StunClientTransaction)clientTransactions[tid];
clientTransactions.Remove(tid);
if (tran != null)
{
tran.HandleResponse(@event);
}
else
{
//do nothing - just drop the phantom response.
}
}
}
/**
* Creates a listening point for the specified socket and attempts to
* discover how its local address is NAT mapped.
* @param socket the socket whose address needs to be resolved.
* @return a StunAddress object containing the mapped address or null if
* discovery failed.
* @throws StunException if something fails along the way.
*/
public virtual StunAddress GetMappingFor(MyUdpClient socket)
{
NetAccessPointDescriptor apDesc = stunStack.InstallNetAccessPoint(socket);
requestSender = new BlockingRequestSender(stunProvider, apDesc);
StunMessageEvent evt = null;
try
{
evt = requestSender.SendRequestAndWaitForResponse(
MessageFactory.CreateBindingRequest(), serverAddress);
}
finally
{
stunStack.RemoveNetAccessPoint(apDesc);
}
if (evt != null)
{
Response res = (Response)evt.GetMessage();
MappedAddressAttribute maAtt =
(MappedAddressAttribute)
res.GetAttribute(Attribute.MAPPED_ADDRESS);
if (maAtt != null)
{
return(maAtt.GetAddress());
}
}
return(null);
}
/**
* Sends a binding request to the specified server address with only change
* port flag set to true and change IP flag - to false.
* @param serverAddress the address where to send the bindingRequest.
* @return The returned message encapsulating event or null if no message
* was received.
* @throws StunException if an exception occurs while sending the messge
*/
private StunMessageEvent doTestIII(StunAddress serverAddress)
{
Request request = MessageFactory.CreateBindingRequest();
ChangeRequestAttribute changeRequest = (ChangeRequestAttribute)request.GetAttribute(Attribute.CHANGE_REQUEST);
changeRequest.SetChangeIpFlag(false);
changeRequest.SetChangePortFlag(true);
StunMessageEvent evt =
requestSender.SendRequestAndWaitForResponse(request, serverAddress);
#if false
if (evt != null)
{
System.oout.println("Test III res=" + evt.getRemoteAddress().toString()
+ " - " + evt.getRemoteAddress().getHostName());
}
else
{
Console.WriteLine("NO RESPONSE received to Test III.");
}
#endif
return(evt);
}
/**
* Called to notify this provider for an incoming message.
* @param event the event object that contains the new message.
*/
public virtual void HandleMessageEvent(StunMessageEvent @event)
{
Message msg = @event.GetMessage();
//request
if(msg is Request)
{
TransactionID serverTid = TransactionID.
CreateTransactionID(msg.GetTransactionID());
serverTransactions.Add(serverTid);
if(requestListener != null)
requestListener.requestReceived(@event);
}
//response
else if(msg is Response)
{
TransactionID tid = TransactionID.
CreateTransactionID(msg.GetTransactionID());
StunClientTransaction tran = (StunClientTransaction)clientTransactions[tid];
clientTransactions.Remove(tid);
if(tran != null)
{
tran.HandleResponse(@event);
}
else
{
//do nothing - just drop the phantom response.
}
}
}
/**
* Does the message parsing.
*/
public virtual void Run()
{
//add an extra try/catch block that handles uncatched errors and helps avoid
//having dead threads in our pools.
try
{
while (isRunning)
{
RawMessage rawMessage = null;
rawMessage = messageQueue.Remove();
// were we asked to stop?
if (!IsRunning())
{
return;
}
//anything to parse?
if (rawMessage == null)
{
continue;
}
Message stunMessage = null;
try
{
stunMessage =
Message.Decode(rawMessage.GetBytes(),
0,
rawMessage.GetMessageLength());
}
catch (StunException ex)
{
errorHandler.HandleError("Failed to decode a stun mesage!",
ex);
continue; //let this one go and for better luck next time.
}
StunAddress sa = new StunAddress(
rawMessage.GetRemoteAddress().GetAddress(),
rawMessage.GetRemoteAddress().GetPort());
sa.Local = rawMessage.GetLocalAddress();
StunMessageEvent stunMessageEvent =
new StunMessageEvent(rawMessage.GetNetAccessPoint(),
stunMessage,
sa);
messageHandler.HandleMessageEvent(stunMessageEvent);
}
}
catch (Exception err)
{
//notify and bail
errorHandler.HandleFatalError(this, "Unexpected Error!", err);
}
}
/**
* Saves the message event and notifies the discoverer thread so that
* it may resume.
* @param evt the newly arrived message event.
*/
public virtual void ProcessResponse(StunMessageEvent evt)
{
Monitor.Enter(this);
try
{
this.responseEvent = evt;
Monitor.PulseAll(this);
}
finally
{
Monitor.Exit(this);
}
}
/**
* Saves the message event and notifies the discoverer thread so that
* it may resume.
* @param evt the newly arrived message event.
*/
public virtual void ProcessResponse(StunMessageEvent evt)
{
Monitor.Enter(this);
try
{
this.responseEvent = evt;
Monitor.PulseAll(this);
}
finally
{
Monitor.Exit(this);
}
}
/**
* Sends the specified request and blocks until a response has been
* received or the request transaction has timed out.
* @param request the reuqest to send
* @param serverAddress the request destination address
* @return the event encapsulating the response or null if no response
* has been received.
* @throws StunException NETWORK_ERROR or other if we fail to send
* the message
*/
public virtual StunMessageEvent SendRequestAndWaitForResponse(
Request request,
StunAddress serverAddress)
{
Monitor.Enter(this);
try
{
stunProvider.SendRequest(request, serverAddress, apDescriptor,
this);
Monitor.Wait(this);
StunMessageEvent res = responseEvent;
responseEvent = null; //prepare for next message
return(res);
}
finally
{
Monitor.Exit(this);
}
}
/**
* Does the message parsing.
*/
public virtual void Run()
{
//add an extra try/catch block that handles uncatched errors and helps avoid
//having dead threads in our pools.
try
{
while (isRunning)
{
RawMessage rawMessage = null;
rawMessage = messageQueue.Remove();
// were we asked to stop?
if (!IsRunning())
return;
//anything to parse?
if (rawMessage == null)
continue;
Message stunMessage = null;
try
{
stunMessage =
Message.Decode(rawMessage.GetBytes(),
0,
rawMessage.GetMessageLength());
}
catch (StunException ex)
{
errorHandler.HandleError("Failed to decode a stun mesage!",
ex);
continue; //let this one go and for better luck next time.
}
StunAddress sa = new StunAddress(
rawMessage.GetRemoteAddress().GetAddress(),
rawMessage.GetRemoteAddress().GetPort() );
sa.Local = rawMessage.GetLocalAddress();
StunMessageEvent stunMessageEvent =
new StunMessageEvent(rawMessage.GetNetAccessPoint(),
stunMessage,
sa);
messageHandler.HandleMessageEvent(stunMessageEvent);
}
}
catch(Exception err)
{
//notify and bail
errorHandler.HandleFatalError(this, "Unexpected Error!", err);
}
}
/**
* Dispatches the response then cancels itself and notifies the StunProvider
* for its termination.
* @param evt the event that contains the newly received message
*/
public virtual void HandleResponse(StunMessageEvent evt)
{
this.Cancel();
this.responseCollector.ProcessResponse(evt);
}
/**
* Sends the specified request and blocks until a response has been
* received or the request transaction has timed out.
* @param request the reuqest to send
* @param serverAddress the request destination address
* @return the event encapsulating the response or null if no response
* has been received.
* @throws StunException NETWORK_ERROR or other if we fail to send
* the message
*/
public virtual StunMessageEvent SendRequestAndWaitForResponse(
Request request,
StunAddress serverAddress)
{
Monitor.Enter(this);
try
{
stunProvider.SendRequest(request, serverAddress, apDescriptor,
this);
Monitor.Wait(this);
StunMessageEvent res = responseEvent;
responseEvent = null; //prepare for next message
return res;
}
finally
{
Monitor.Exit(this);
}
}
/**
* Dispatches the response then cancels itself and notifies the StunProvider
* for its termination.
* @param evt the event that contains the newly received message
*/
public virtual void HandleResponse(StunMessageEvent evt)
{
this.Cancel();
this.responseCollector.ProcessResponse(evt);
}
/**
* Implements the discovery process itself (see class description).
* @return a StunDiscoveryReport containing details about the network
* configuration of the host where the class is executed.
* @throws StunException ILLEGAL_STATE if the discoverer has not been started
* NETWORK_ERROR or ILLEGAL_ARGUMENT if a failure occurs while executing
* the discovery algorithm
*/
virtual public StunDiscoveryReport determineAddress()
{
checkStarted();
StunDiscoveryReport report = new StunDiscoveryReport();
StunMessageEvent evt = doTestI(serverAddress);
if (evt == null)
{
//UDP Blocked
report.SetNatType(StunDiscoveryReport.UDP_BLOCKING_FIREWALL);
return(report);
}
else
{
StunAddress mappedAddress = ((MappedAddressAttribute)evt.GetMessage().
GetAttribute(Attribute.MAPPED_ADDRESS)).GetAddress();
StunAddress backupServerAddress = ((ChangedAddressAttribute)evt.GetMessage().
GetAttribute(Attribute.CHANGED_ADDRESS)).GetAddress();
report.SetPublicAddress(mappedAddress);
if (mappedAddress.Equals(apDescriptor.GetAddress()))
{
evt = doTestII(serverAddress);
if (evt == null)
{
//Sym UDP Firewall
report.SetNatType(StunDiscoveryReport.SYMMETRIC_UDP_FIREWALL);
return(report);
}
else
{
//open internet
report.SetNatType(StunDiscoveryReport.OPEN_INTERNET);
return(report);
}
}
else
{
evt = doTestII(serverAddress);
if (evt == null)
{
evt = doTestI(backupServerAddress);
if (evt == null)
{
// System.oout.println("Failed to receive a response from backup stun server!");
return(report);
}
StunAddress mappedAddress2 = ((MappedAddressAttribute)evt.GetMessage().
GetAttribute(Attribute.MAPPED_ADDRESS)).GetAddress();
if (mappedAddress.Equals(mappedAddress2))
{
evt = doTestIII(serverAddress);
if (evt == null)
{
//port restricted cone
report.SetNatType(StunDiscoveryReport.PORT_RESTRICTED_CONE_NAT);
return(report);
}
else
{
//restricted cone
report.SetNatType(StunDiscoveryReport.RESTRICTED_CONE_NAT);
return(report);
}
}
else
{
//Symmetric NAT
report.SetNatType(StunDiscoveryReport.SYMMETRIC_NAT);
return(report);
}
}
else
{
//full cone
report.SetNatType(StunDiscoveryReport.FULL_CONE_NAT);
return(report);
}
}
}
}
