The session param "client_ip" will be empty when using the HTML client:
> bash-4.3$ tl-session-param /client_ip
We can probably fix this, but it's not trivial. The way it works is that the master digs around in /proc/<pid>/environ for the process that does the XML-RPC calls, looking for SSH_CONNECTION. We can easily set that environment variable, but /proc isn't updated until we do exec(), which we never do.
So we need to do either:
a) Change the mechanism in the master somewhat to accommodate the HTML client
b) Inject an exec somewhere in the HTML client, e.g. by doing the XML-RPC communication via thinlinc-login instead of directly.