allow process or user to listen on priviledged ports?

["Sven Köhler" <skoehler@upb.de>]

Hi,

don't blame me for asking such a question in the LKML, but i already 
asked it in other linux-newsgroups. i haven't got any real answer yet.

my problem is, that i want an application to listen on a priviledged 
port (e.g. port 80) and to run as a "normal" unpriviledged user (e.g. 
wwwrun). Well - how? The application is not a C/C++-application, so i 
cannot ask the author (myself) to implement a mechanism to switch the 
userid (e.g. like apache does it).

So is there any machanism to bind that permission (to listen on a 
priviledged tcp-port) to a specific user or a specific process?

The application is written in Java. Of course Java could implement 
userid-switching, but the linux could also have an ACL for that. So 
please don't answer with "go and ask Sun for that feature". I already 
considered that.

Thx
   Sven