Binding a port < 1024 for non root user in Java

Question

I have a Java application which is running as non root mode.

My App will create a TFTP server (using apache commons tftp). TFTP server is bind to port 69(Default TFTP port). When running the app from IDE everything works fine since the IDE running as root. But if the app is run from other user i get the error

java.net.BindException: Permission denied

It is clear that for non root user i can not open the port. Is there a workaround for this issue?

I think it is not possible. I also tried a lot for this but I could not do it. — Ravindra Gullapalli, Mar 22 '12 at 09:26
Oh. I need to port 69 since the third party app will send a file to port 69 :( — Dheeraj Joshi, Mar 22 '12 at 09:28
Java is not relevant here, this is a much wider issue. See http://stackoverflow.com/questions/413807/is-there-a-way-for-non-root-processes-to-bind-to-privileged-ports-1024-on-l — skaffman, Mar 22 '12 at 09:33

score 4 · Accepted Answer · answered Mar 22 '12 at 09:30

4

For binding on Linux of ports less that 1024 you need to application to run a root. There is no way around this. If you need to do this you have you run as root. sudo might be the command to look into.

BTW - Running your IDE as root is not a very good idea.

answered Mar 22 '12 at 09:30

Ed Heal

59,252
17
87
127

My device is **rooted** and the app is in `system/priv-app` but still can not bind ports less than 1024. – MHSaffari Dec 26 '20 at 11:47

score 2 · Answer 2 · edited Mar 24 '14 at 17:20

2

To resolve this issue. You can use setuid() and setfid() system calls. So that you can temporarily elevate the permissions and then drop the permission back to user permissions.

edited Mar 24 '14 at 17:20

Erik Kaplun

37,128
15
99
111

answered Apr 25 '12 at 07:51

Dheeraj Joshi

3,057
8
38
55

score 1 · Answer 3 · answered Oct 08 '18 at 20:11

1

In my Case, this problem happened in Solaris 11 OS. I added privileges to user to use the ports under 1024.

https://technicalsanctuary.wordpress.com/2014/06/03/allowing-a-user-to-use-ports-under-1024-on-solaris-11/

answered Oct 08 '18 at 20:11

Christian Alvarado

21
1

Binding a port < 1024 for non root user in Java

3 Answers3