How can I log screen sharing access on OS X?

I've got my firewall on (the OS X firewall) and I've got a lot of attempts on screen sharing.

Allow AppleVNCServer connecting from 93.78.170.237:2223 uid = 0 proto=6

I want to log successful connections to make sure no one is making it through, similar to what is done with /var/log/secure.log

In fact, I'm surprised this isn't included with secure.log

What can I do?

For what its worth, I am running Mac OS X 10.5.8.

Update 1:

Daniel had a nice suggestion to use

netstat -a | grep vnc | grep ESTABLISHED

redirected to a file to log what is going on.

The problem is a connection is flagged as ESTABLISHED as soon as the vnc login screen comes up regardless of whether or not a login is ultimately successful.

In other words, all those (hopefully) failed attempts that my firewall logs will look no different than my successful logins.

Solution 1:

You can very easily extend the script that was suggested to me in another question to solve my need for notifications when VNC connections were established.

Basically, replace the notification aspect of the script with a line that writes to a log file.

Solution 2:

Screen shares are logged in /var/log/secure.log