FTP Upload Binding Error

Add-ons Bindings
1

Hello,
I’m using the FTP Upload binding on openHAB 2.5.0.
When I try to change the default listening port of the binding (2121 to 21), I receive the following error:

2020-04-11 10:14:07.752 [INFO ] [oad.internal.FtpUploadHandlerFactory] - Stopping FTP server
2020-04-11 10:14:07.772 [INFO ] [oad.internal.FtpUploadHandlerFactory] - Stopping FTP server
2020-04-11 10:14:07.775 [INFO ] [oad.internal.FtpUploadHandlerFactory] - Starting FTP server, port=21, idleTimeout=60
2020-04-11 10:14:07.792 [WARN ] [oad.internal.FtpUploadHandlerFactory] - FTP server starting failed, reason: Failed to bind to address 0.0.0.0/0.0.0.0:21, check configuration

Could you please help.

Thanks,

2

Where are you making the changes to the port? In the logs it shows only 0’s for the IP. :thinking:

3

I did it via the paper UI -> Configuration -> Bindings -> FTP Upload Binding.
The error appears when I choose 21 or 22 as a new port. On the other hand, when I choose another port for example 2222 or another one it works without any issue.
Thank you,

4

Is there a firewall setting that has ports other than 21 and 22 blocked?

5

You didn’t say which OS you running, but in Linux, you need root privileges to be able to bind TCP/UDP port below 1024.

6

To my knowledge, there is no Firewall installed.
I did a basic installation of my raspberry and I only installed the prerequisites of openhab.

7

Check your router setting. :upside_down_face:

8

Thank you Pauli,
pi@server3:/etc $ sudo uname -a
Linux server3 4.19.66-v7+ #1253 SMP Thu Aug 15 11:49:46 BST 2019 armv7l GNU/Linux

I just tried to forward port 21 to 2121 and it is working. It can be a workaround.
Have you any other suggestion please.

9

Have you any other suggestion please.

You could try to give CAP_NET_BIND_SERVICE capabilities to app via setcap, but I guess you need to give them to java.

http://manpages.ubuntu.com/manpages/xenial/man8/setcap.8.html
http://manpages.ubuntu.com/manpages/xenial/man7/capabilities.7.html