search for: peercredentials

I've a server where clients can connect to using direct-streamlocal at openssh.com. I want that the server "knows" the address of the client. I've tried using the peercredentials of the process connecting my server (which is a sshd process) and check the environment. I thought that in the environment the var SSH_CLIENT would be set, but that did not work. This sshd process has an almost empty environment file. Is there another good way to find it? Thanks in advance, Stef...