Remote Port Forwarding

[Kevin Day]

I'm trying to use mina sshd in a remote port forwarding scenario:

Client connects to Server on port 22
Traffic inbound to Server port 12345 gets forwarded to Client port 9876

I'm running into a problem where the connection to port 12345 on the server 
gets refused.  I've traced the issue to this line in TcpipServerChannel:

final ForwardingFilter filter = 
getSession().getFactoryManager().getTcpipForwardingFilter();
if (address == null || filter == null || !filter.canConnect(address, 
getSession())) {


the problem is that filer is winding up with a null value.  The problem is that 
I don't see any way to get that value set.



My client code:

SshClient client = SshClient.setUpDefaultClient();
client.start();

try{
ConnectFuture sessionFuture = client.connect("localhost", 22);
sessionFuture.await();
ClientSession session = sessionFuture.getSession();
AuthFuture authPassword = session.authPassword("user", "pass");
authPassword.await();
if(!authPassword.isSuccess()) throw new Error("Authentication failed");

SshdSocketAddress local = new SshdSocketAddress("localhost", 14722);
SshdSocketAddress remote = new SshdSocketAddress("localhost", 14730);

SshdSocketAddress remoteConnectInfo = 
session.getTcpipForwarder().startRemotePortForwarding(remote, local);

System.out.println("Forwarding " + remoteConnectInfo + " to " + local);




and the server code:



SshServer sshd = SshServer.setUpDefaultServer();
sshd.setPort(22);
File keyFile = new File("devapphome/config/hostkey.ser").getAbsoluteFile();
sshd.setKeyPairProvider(new 
SimpleGeneratorHostKeyProvider(keyFile.getAbsolutePath()));
sshd.setPasswordAuthenticator(new PasswordAuthenticator(){

@Override
public boolean authenticate(String username, String password, ServerSession 
session) {
return "user".equals(username) && "pass".equals(password);
}

});




sshd.setTcpipForwardingFilter(new ForwardingFilter() {

@Override
public boolean canListen(SshdSocketAddress address, Session session) {
System.out.println("Listen request from " + address);
return true;
}

@Override
public boolean canForwardX11(Session session) {
return true;
}

@Override
public boolean canForwardAgent(Session session) {
return true;
}

@Override
public boolean canConnect(SshdSocketAddress address, Session session) {
System.out.println("Connection request from " + address);
return true;
}
});

try {
sshd.start();
System.out.println("sshd started - listening on port " + sshd.getPort());

synchronized (this) {
wait();
}
} catch (IOException | InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}



The problem is that sshd.setTcpipForwardingFilter sets the filter on the 
SshServer side of things.  In remote port forwarding mode, a totally different 
(SshClient-side sub-class of AbstractChannel - AbstractClientChannel) Session 
object is being created, and it doesn't look like it is inheriting the 
TcpipForwardingFilter.



Am I missing something here?  Do I need to be adding some sort of registration 
to detect remote port forwarding requests and configure the 
AbstractClientChannel somehow?


Thanks much,

- Kevin