[SSHD-1293] ExplicitPortForwardingTracker does not unbind auto-allocated one

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.8.0
• Fix Version/s: 2.9.2
• Assignee: Unassigned
• Reporter: Jan Philipp
• Created: 30/Aug/22 11:56
• Updated: 20/Sep/22 13:25
• Resolved: 20/Sep/22 13:25

Description

I have noticed that the de-allocation (unbind of a forwarding) initiated by org.apache.sshd.client.session.forward.ExplicitPortForwardingTracker in the close() method will not no close the actual forwarding. Said that, this leaves the connection and a file handler open.

The actual main reason is that it uses manager.stopLocalPortForwarding(this.getLocalAddress()); which means it stops the tunnel identified the "local address" which is the same as provided by the user. If the user is using a local address with port 0 (which seems legit since the docs state this explicitly), the local address will be still something like 0.0.0.0:0 or maybe 127.0.0.1:0, but only the "bound address" contains the actual dynamic auto-allocated port.

If the user uses an explicit port, this would work.

As a workaround, I have added after tracker.close() an explicit session.stopLocalPortForwarding(tracker.getBoundAddress()). I don't know if this would your final solution or this would be an issue in DefaultForwarder#stopLocalPortForwarding.

 

I'm using 2.8 right now; as far as I can see there are no changes in 2.9 regarding this.