Hi All,

I have now started doing socket programming in linux.
I have a server and client tasks with the client bound to the socket(Datagram). The client and server would then send messages.
However, I need the server to know the "Pid" of the client talking with it.
How is this possible? Can I get this info from some structure that can be passed by the client to the server during a sendto()?

Thanks in advance!

Hi, why do not simply send the process id reported by getpid() as normal data or control data using sendto, when the client establishes the connection?

I just had a project like this last semester
Your "server" doesn't need to know the PID of the "client" to connect, so i would just do as irmin suggested and have the client getpid(), then send it to the server.

Hi all,

Thanks for your suggestions. Actually, shouldn't the server know who its clients are?

I am currently writing a sort of filter server which allows only genuine clients and blocks malicious clients.

Of course, the term genuine and malicious are found depending on what information the clients ask. If the clients are found to be malicious, then the server has to do a 'POSIX' kill on the client (using its PID).

I have no linux experience but have worked with QNX where I use message passing(not sockets) and there was a client info struct
that gave the client pid.

Can you guys help me?

If the client is an external system talking to your socket, then there is no process on the server that corresponds to the client. Your server just has to check eg ip addr and you can write it so that it expects a password and dumps the cxn if it's invalid.
Even if you ran the client SW on the same box, the same rule applies. You don't kill the client process even the, just refuse/ignore the cxn if its 'bad/invalid'.