The listen() call never rejects and always listens on 0.0.0.0

[TimLuq]

listen() never rejects

The callback to (net | tls).server.listen will not receive an error argument, but is instead attached as a callback to the "listening" event. When there is a binding error listening will never be dispatched and the promise is dead and will never reject nor resolve.

See https://nodejs.org/api/net.html#net_server_listen

listen() always listens to 0.0.0.0

No host is passed on to the net.server.listen(), as such the default 0.0.0.0 is always bound.

[trs]

#86

[sbstnbr]

Hi @trs @TimLuq,

This fix breaks my use case where my FTP is deployed behind a TCP Router which reroutes client connection to it (like a load balancer).

In my case, the hostname I provide while starting the server is the public IP of the TCP Router, which is sent back to the client when he wants to push files.
But my FTP server now fails at startup because it tries to listen to this same IP (which is normal) instead of 0.0.0.0.

{"message":"listen EADDRNOTAVAIL ",
"name":"Error","stack":"Error: listen EADDRNOTAVAIL :\n at Object._errnoException
(util.js:1022:11)\n at _exceptionWithHostPort (util.js:1044:20)\n at Server.setupListenHandle [as _listen2]
(net.js:1334:19)\n at listenInCluster (net.js:1392:12)\n at doListen (net.js:1501:7)\n at _combinedTickCallback
(internal/process/next_tick.js:141:11)\n at process._tickCallback (internal/process/next_tick.js:180:9)",
"code":"EADDRNOTAVAIL"},"msg":"[Event] error","time":"2018-05-22T10:14:39.374Z","v":0}

Would it be posible to configure 2 kind of hostnames ?

• the listening hostname
• the hostname to which the client should send files

[trs]

@sbstnbr Thank you for your report, I was worried there would be broken builds. I apologize for it.

I think I have a solution:

• The server and any passive connections will listen on the provided hostname in url. Even if this is 0.0.0.0.
• The hostname which to send to the client (via the PASV command) will be the url hostname or an optional pasv_url value. If this value is 0.0.0.0, it will then resolve to the external IP.

What do you think?

[sbstnbr]

Works for me ! 👍