Hi,

I'm trying to write a program which will dyanmically open the firewall for ports open by a specific program (using the libipq library).

for this i need a way to figure out the process id, user id which has created the specific listening socket for a given port (like lsof does). i tried to go through the lsof code but it seems too complicated + since lsof is not gpl i dont have a clear idea what effect it will have on the program that i make (which i plan to make gpl). i realise that i could call lsof from my code but i feel it would give put too much overhead in the process.

can anyone give me some idea as to what i need? this is really my first real linux program so i dont have much of a idea of where to look (google didnt help).

thanks
--MAS

Try the sources of "netstat" instead of lsof. It's probably simpler and also GPL.

Example: netstat -plan
gives all connected and listening sockets (tcp, udp, and filesy sockets) including PID, and process name. (when not run as root, it will give you this info only for the processes of the user running netstat, but there's no way around that anyway)

"netstat" is (on debian) part of the "net-tools" package. One place to get the sources: http://ftp.debian.org/debian/pool/ma...60.orig.tar.gz

many thanks. i'll go through the code.