/**
* 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);
}
/**
* 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);
}
/**
* 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.
}
}
}
/**
* 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.
}
}
}
/**
* 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);
}
}
}
}
