Apps Getting application on a specific port

[amiturgman]

I have an android native application which hosts a web server inside it.
I want to know which application makes requests before they are processed by my application.
What I have is the port of the calling application.

How can I find out which application is using this port?
I've tried looking for all processes (cat /proc/net/tcp6), but the application with the port I have is not listed (on a rooted device it is).

I need to find a way to find the calling application name on a regular device (not rooted).

Any help is highly appriciated.

Thanks!
Ami.