[FTPSERVER-300] Create an extensible getPassiveExternalAddress() method in PASV command so ftp integrators can define additional ways to obtain their 'external passive address'.

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.0.2
• Assignee: David Latorre
• Reporter: David Latorre
• Created: 14/May/09 12:13
• Updated: 30/May/09 16:13
• Resolved: 14/May/09 15:45

Description

PASV command will return the server's ip address and a port number to the client in order for this to initiate a new data connection.

In the case we are behind a NAT proxy, we need to figure out what is the IP address the client is actually connecting to. For this, ftpserver provides a configuration option to establish the IP address which will be returned after a PASV command is sent.

This method will work in a number of cases but it is not enough in several others , e.g., if the server has a dynamic ip or if different users see different ips for the same machine ( which can be the case, it is my case actually) .

So we might add a protected method getExternalPassiveAddress() in PASV command implementation so the external ip guessing can be customized as needed by extenders. Otherwise, the whole Passive method should be re-implemented.